JP5982749B2 - Focus adjustment device and imaging device - Google Patents

Description

  The present invention relates to a focus adjustment device and an imaging device.

  2. Description of the Related Art Conventionally, imaging devices capable of moving image shooting are known. In such an imaging apparatus, in order to continuously capture a focused image of a subject, a technique is disclosed in which focus adjustment is repeatedly performed by driving a focus adjustment lens during moving image shooting (for example, a patent). Reference 1).

JP 2008-287050 A

  However, in the conventional technology, it is necessary to always drive the focus adjustment lens during moving image shooting for focus adjustment, and by constantly driving the focus adjustment lens, many lens driving sounds (abnormal noise) are generated. There was a problem that many lens driving sounds were recorded as noise.

  The problem to be solved by the present invention is to provide a focus adjustment device capable of appropriately adjusting the focus of an optical system.

  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] focusing device according to a first aspect of the present embodiment, the first mode is set to the still image shooting or the second mode Selectable selector you shooting a movie, the focus position a phase difference detecting section for detecting a phase difference to compute, when moving the full Okasurenzu to calculate the focus position using the phase difference detection unit, using the output of the phase difference detection section When the first mode is selected by the selection unit when the focus lens is moved to the calculated focus position and when the focus lens is moved to a position where a subject is expected to move The focus lens is moved at a first speed, and the focus lens is moved at a second speed slower than the first speed when the second mode is selected by the selection unit and a preparation for photographing is performed. And a control unit for moving the focus lens at a slower third rate than the second speed when the second mode by the selection unit is not the operation of said selected shooting preparation.

[2] focusing device according to the second aspect of the present embodiment, the first mode is set to the still image shooting or the second mode Selectable selector you shooting a movie, the focus position a phase difference detecting section for detecting a phase difference to compute, in the case of moving the full Okasurenzu to calculate the focus position using the phase difference detection unit, the first mode by the selection unit The focus lens is moved at a first speed when selected, and the second speed is slower than the first speed when the second mode is selected by the selection unit and a shooting preparation operation is performed. in moving, we have a, and a control unit for moving the focus lens at a slower third rate than the second speed when the second mode is not the operation of said selected photographic preparation by the selection unit, Control When the focus lens is moved to a position where the subject is expected to move, the focus lens is moved at a seventh speed when the first mode is selected by the selection unit, and the selection unit When the second mode is selected and the shooting preparation operation is performed, the focus lens is moved at an eighth speed slower than the seventh speed, and the second mode is selected by the selection unit and the shooting preparation operation is performed. When not, the focus lens is moved at a ninth speed that is slower than the eighth speed.

  According to the present invention, it is possible to appropriately adjust the focus of the optical system.

FIG. 1 is a block diagram showing a camera according to the first embodiment. FIG. 2 is a front view showing an 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 an operation when the AF-S mode is selected. FIG. 10 is a diagram illustrating the relationship between the focus lens position and the focus evaluation value and the relationship between the focus lens position and time in the scanning operation. FIG. 11 is a flowchart (part 1) showing the operation when the AF-F mode is selected. FIG. 12 is a flowchart (part 2) illustrating the operation when the AF-F mode is selected.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  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 moves in the direction of the optical axis L <b> 1 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 infinity end) by the rotation of the rotating cylinder described above. Can do. 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. Adjustment of the aperture diameter by the diaphragm 34 is performed, for example, by sending a signal according to the diaphragm value calculated by the camera control unit 21 from the camera control unit 21 via the lens control unit 37. Further, the set aperture diameter is input from the camera control unit 21 to the lens control unit 37 by a 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.

  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.

  The camera body 2 is provided with an observation optical system for observing an image picked up by the image pickup device 22. The observation optical system of the present embodiment includes an electronic viewfinder (EVF) 26 composed of a liquid crystal display element, a liquid crystal driving circuit 25 that drives the electronic viewfinder (EVF) 26, and an eyepiece lens 27. The liquid crystal drive circuit 25 reads the captured image information captured by the image sensor 22 and sent to the camera control unit 21, and drives the electronic viewfinder 26 based on the read image information. Thereby, the user can observe the current captured image through the eyepiece lens 27. Note that, instead of or in addition to the observation optical system using the optical axis L2, a liquid crystal display may be provided on the back surface of the camera body 2, and a photographed image may be displayed on the liquid crystal display.

  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 photographic optical system by the phase detection method and the focus state of the photographic optical system by the contrast detection method based on the pixel data read from the image sensor 22. I do. A specific focus state detection method will be described later.

  The operation unit 28 is an input switch for a photographer to set various operation modes of the camera 1, such as a shutter release button and a moving image shooting start button, and switches between an autofocus mode / manual focus mode and an autofocus mode. In particular, the AF-S mode / AF-F mode can be switched. 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.

  Here, the AF-S mode is to fix the position of the focus lens 32 once adjusted after the focus lens 32 is driven based on the focus detection result when the shutter release button is pressed halfway. In this mode, shooting is performed at the focus lens position. The AF-S mode is a mode suitable for still image shooting, and is normally selected when still image shooting is performed. In the AF-F mode, the focus lens 32 is driven based on the focus detection result regardless of whether or not the shutter release button is operated, and then the focus state is repeatedly detected. In this mode, the focus lens 32 is scanned. The AF-F mode is a mode suitable for moving image shooting, and is usually selected when moving image shooting is performed.

  In the present embodiment, the switch for switching the autofocus mode may be provided with a switch for switching the one-shot mode / continuous mode. In this case, when the one-shot mode is selected by the photographer, the AF-S mode is set, and when the continuous mode is selected by the photographer, the AF-F mode is set. It can be set as such.

  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, a 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 area. 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 focal plane corresponding to the current focal plane (the position corresponding to the position of the microlens array on the planned focal plane) The deviation of the focal plane in the detection area), 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 by, for example, extracting a high frequency component of an image output from the imaging pixel 221 of the imaging element 22 using a high frequency transmission filter and integrating the extracted high frequency component. It can also be obtained by extracting high-frequency components using two high-frequency transmission filters having different cutoff frequencies and integrating them.

  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. First, in the present embodiment, an operation example when the AF-S mode, which is a mode suitable for still image shooting, is selected will be described. FIG. 9 is a flowchart showing an operation when the AF-S mode is selected. Note that since the AF-S mode is normally a mode that is selected when still image shooting is performed, the following description will be given specifically illustrating a scene in which the AF-S mode is selected during still image shooting. To do. Further, the following operation is started, for example, when the camera 1 is turned on.

  First, in step S101, the camera control unit 21 starts a defocus amount calculation process using a phase difference detection method. In the present embodiment, the calculation process of the defocus amount by the phase difference detection method is performed as follows. That is, first, the camera control unit 21 reads a pair of image data corresponding to a pair of images from each of the focus detection pixels 222a and 222b constituting the three focus detection pixel rows 22a to 22c of the image sensor 22. 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. Note that the reliability of the defocus amount is evaluated based on, for example, the degree of coincidence and contrast of a pair of image data. The defocus amount calculation process using such a phase difference detection method is repeatedly executed at predetermined intervals.

  In step S102, the camera control unit 21 starts a focus evaluation value calculation process. In the present embodiment, the focus evaluation value calculation process is performed by reading out the pixel output of the imaging pixel 221 of the imaging element 22, extracting a high-frequency component of the read-out pixel output using a high-frequency transmission filter, and accumulating these. Done. The focus evaluation value calculation process is repeatedly executed at predetermined intervals.

  In step S103, the camera control unit 21 determines whether or not the shutter release button provided in the operation unit 28 is half-pressed (the first switch SW1 is turned on). If the first switch SW1 is turned on, the process proceeds to step S104. On the other hand, if the first switch SW1 is not turned on, step S103 is repeated until the first switch SW1 is turned on. That is, the defocus amount calculation process and the focus evaluation value calculation process by the phase difference detection method are repeatedly executed until the first switch SW1 is turned on.

  In step S104, the camera control unit 21 determines whether or not the defocus amount can be 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 S109. On the other hand, if the defocus amount cannot be calculated, it is determined that distance measurement is impossible, and the process proceeds to step S105. In the present embodiment, even when 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 S105. 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. .

  If it is determined in step S104 that the defocus amount can be calculated, the process proceeds to step S109, and the camera control unit 21 performs servo drive for driving the focus lens 32 to a position corresponding to the calculated defocus amount. . Specifically, the camera control unit 21 calculates a lens driving amount necessary to drive the focus lens 32 to the in-focus position based on the calculated defocus amount, and calculates the calculated lens driving amount as It is sent to the focus lens drive motor 36 via the lens control unit 37. Thereby, the focus lens drive motor 36 performs servo drive for driving the focus lens 32 to the in-focus position based on the calculated lens drive amount.

In addition, when performing servo drive, the camera control unit 21 performs control to drive the focus lens 32 at the first servo speed V _Servo1 . Specifically, the camera control unit 21 sends a drive pulse signal corresponding to the first servo speed V _Servo1 to the focus lens drive motor 36 so that the focus lens 32 is moved to the first servo by the focus lens drive motor 36. Drive at speed V _Servo1 . Here, the first servo speed V _Servo1 is the drive speed of the focus lens 32 when performing servo drive during still image shooting, and can be, for example, the maximum drive speed of the focus lens 32. Thereby, in this embodiment, the focus lens 32 can be driven to the focus position detected by the phase difference detection method in a short time during still image shooting.

In this embodiment, even after the servo drive of the focus lens 32 is started, the defocus amount is repeatedly calculated at a predetermined interval, and as a result, a new defocus amount is calculated. The focus lens 32 is servo-driven based on the newly calculated defocus amount. Also in this case, the focus lens 32 is driven at the first servo speed V _Servo1 .

  In step S109, when the focus lens 32 is driven to the in-focus position corresponding to the defocus amount, the process proceeds to step S112, and the camera control unit 21 performs focus lock (processing for prohibiting driving of the focus lens 32). ) Is performed.

  On the other hand, if it is determined in step S104 that the defocus amount cannot be calculated, or if it is determined that the reliability of the calculated defocus amount is low, the process proceeds to step S105, and in step S105, the camera The control unit 21 performs a scan operation start process. In the scan operation of this embodiment, the focus lens drive motor 36 scans the focus lens 32, and the camera control unit 21 calculates a defocus amount and a focus evaluation value by a phase difference detection method. 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.

  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. Note that the scan driving 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.

  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.

Further, when performing scan driving, the camera control unit 21 performs control to drive the focus lens 32 at the first scan speed V _Scan1 . Specifically, the camera control unit 21 sends a drive pulse signal corresponding to the first scan speed V _Scan1 to the focus lens drive motor 36, so that the focus lens 32 is first scanned by the focus lens drive motor 36. Drive at speed V _Scan1 . Here, the focus detection by the contrast detection method is to calculate a focus evaluation value at a predetermined sampling interval while driving the focus lens 32 to scan. The sampling interval of the focus evaluation value increases as the driving speed of the focus lens 32 increases. When the driving speed of the focus lens 32 exceeds a predetermined speed, the sampling interval of the focus evaluation value increases. Thus, the in-focus position cannot be detected properly. In the present embodiment, the maximum speed among the speeds at which the focus position by the contrast detection method can be appropriately detected can be set to the first scan speed V _Scan1 , for example. By performing scan driving at such a first scan speed V _Scan1 , it is possible to reduce the time required for scan driving during still image shooting, and as a result, it is possible to reduce the time required for focus adjustment.

Note that the camera control unit 21 calculates the defocus amount and the focus evaluation value while performing the wobbling drive that finely reciprocates the focus lens 32 in the optical axis direction before performing the scan drive. Based on the result, the driving direction of the focus lens 32 in the scan driving can be determined. Further, when performing the wobbling drive, the camera control unit 21 causes the focus lens 32 to perform a wobbling drive at a predetermined first wobbling speed _VWobb1 .

  In step S106, it is determined whether or not the defocus amount can be 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 S109. 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 S107. . In step S106, similarly to step S104 described above, even when the defocus amount can be calculated, the defocus amount cannot be calculated if the reliability of the calculated defocus amount is low. It is assumed that the process proceeds to step S107.

  In step S107, the camera control unit 21 determines whether or not the in-focus position has been detected by the contrast detection method as a result of the scanning operation. If the in-focus position can be detected by the contrast detection method, the process proceeds to step S110. If the in-focus position cannot be detected, the process proceeds to step S108.

  In step S <b> 108, the camera control unit 21 determines whether or not the scan operation has been performed over 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 S106, and steps S106 to S108 are repeated to perform the scan operation, that is, while the focus lens 32 is driven to scan. 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 S111.

As a result of executing the scanning operation, if it is determined in step S106 that the defocus amount can be calculated by the phase difference detection method, the scanning operation is stopped and then the process proceeds to step S109, as described above. Servo driving for driving the focus lens 32 is performed at the first servo speed V _Servo1 up to a position corresponding to the defocus amount calculated by the phase difference detection method.

  As a result of executing the scanning operation, if it is determined in step S107 that the in-focus position has been detected by the contrast detection method, the scanning operation is stopped and then the process proceeds to step S110, where the detection is performed by the contrast detection method. Focusing driving for driving the focus lens 32 is performed up to the focused position.

Here, FIG. 10 is a diagram illustrating the relationship between the focus lens position and the focus evaluation value and the relationship between the focus lens position and time when the in-focus position is detected by the contrast detection method as a result of the scanning operation. Show. As shown in FIG. 10, at the start of the scanning operation, the focus lens 32 is located at P0 shown in FIG. 10, and the focus lens is moved from P0 toward the near side at the first scan speed V _Scan1 from the infinity side. The focus evaluation value is acquired while driving 32. When the focus lens 32 is moved to the position P1 shown in FIG. 10 and the peak position (focus position) of the focus evaluation value is detected (step S107 = Yes), the scanning operation is stopped. Focus drive (step S110) for driving the focus lens 32 to the focus position (position P2 in FIG. 10) is performed.

Further, when performing the focus drive, the camera control unit 21 _drives the focus lens 32 to the focus position at the first focus speed V _Focus1 . Specifically, the camera control unit 21 sends a drive pulse signal corresponding to the first focus speed V _Focus1 to the focus lens drive motor 36, so that the focus lens 32 is moved to the first position by the focus lens drive motor 36. Drive at a focusing speed V _Focus1 . Here, the first focus speed V _Focus1 is the drive speed of the focus lens 32 when performing focus drive during still image shooting, and can be, for example, the maximum drive speed of the focus lens 32. Thereby, in the present embodiment, the focus lens 32 can be driven to the in-focus position detected by the contrast detection method in a short time during still image shooting.

  When the focus lens 32 is driven to the in-focus position detected by the contrast detection method, the process proceeds to step S112, and the camera control unit 21 performs focus lock (processing for prohibiting the drive of the focus lens 32). Is called.

  On the other hand, if it is determined in step S108 that the scan operation has been completed for the entire driveable range of the focus lens 32, the process proceeds to step S111. In step S111, 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 S112. Focus lock is performed.

  In step S113, the camera control unit 21 determines whether or not the shutter release button is fully pressed (the first switch SW2 is turned on). If the second switch SW2 is on, the process proceeds to step S114, and a subject image is captured. On the other hand, if the second switch SW2 is turned off, the process waits in step S113.

  In the present embodiment, the operation is performed as described above when the AF-S mode, which is a mode suitable for still image shooting, is selected.

  Next, an operation example when the AF-F mode, which is a mode suitable for moving image shooting, is selected will be described. 11 and 12 are flowcharts showing the operation when the AF-F mode is selected. Note that since the AF-F mode is a mode that is usually selected when shooting a moving image, the following description will be given specifically illustrating a scene in which the AF-F mode is selected during moving image shooting. The following operations are started when, for example, the camera 1 is turned on and the moving image shooting start button is turned on.

  It should be noted that the camera 1 according to the present embodiment uses the focus lens 32 at the image plane moving speed and the focus lens at the time of still image shooting so that the moving image can be shot with good appearance when moving images are shot. It is driven at a speed slower than the driving speed of 32. In addition, the camera 1 according to the present embodiment can focus on the subject in a short time even when shooting a movie when the shutter release button is half-pressed during movie shooting. Are driven at a speed faster than the drive speed of the focus lens 32 when the shutter release button is not half-pressed at the time of moving image shooting at the image plane moving speed. Hereinafter, the operation of the camera 1 during moving image shooting will be described.

  First, in steps S201 and S202 shown in FIG. 11, similarly to steps S101 and S102 of FIG. 9, a defocus amount calculation process and a focus evaluation value calculation process by the phase difference detection method are started.

  In step S203, the camera control unit 21 determines whether or not the shutter release button provided in the operation unit 28 is half-pressed (the first switch SW1 is turned on). If the first switch SW1 is not turned on, the process proceeds to step S204 in order to perform moving image shooting giving priority to the appearance of the moving image. On the other hand, if the first switch SW1 is turned on, Also, the process proceeds to step S301 in FIG. 12 so that the subject is focused in a short time.

  In step S204, as in step S104 of FIG. 9, it is determined whether or not the defocus amount can be calculated by the phase difference detection method. If the defocus amount can be calculated, it is determined that distance measurement is possible. Then, the process proceeds to step S209. On the other hand, if the defocus amount cannot be calculated, it is determined that distance measurement is impossible, and the process proceeds to step S205.

If it is determined in step S204 that the defocus amount has been calculated, the process proceeds to step S209, and servo drive that drives the focus lens 32 to a position corresponding to the calculated defocus amount is performed, as in step S109 in FIG. Is done. When performing servo drive in step S209, the camera control unit 21 drives the focus lens 32 to the in-focus position at the third servo speed V _Servo3 . Here, the third servo speed V _Servo3 is a speed slower than the first servo speed V _Servo1 at the time of still image shooting. For example, the change in the shot image by driving the focus lens 32 becomes a predetermined value or less. It can be speed. Thereby, in this embodiment, at the time of moving image shooting, a change in the shot image due to driving of the focus lens 32 is reduced, and a moving image with good appearance can be shot even while servo driving is performed.

In step S209, as in step S109 of FIG. 9, the defocus amount is repeatedly calculated at a predetermined interval even after servo drive of the focus lens 32 is started. When the focus amount is calculated, the focus lens 32 is servo-driven at the third servo speed V _Servo3 based on the newly calculated defocus amount. When the focus lens 32 is driven to the in-focus position corresponding to the defocus amount, the process proceeds to step S212.

On the other hand, if it is determined in step S204 that the defocus amount cannot be calculated, or if it is determined that the reliability of the calculated defocus amount is low, the process proceeds to step S205, and step S105 in FIG. 9 is performed. Similarly to the above, a scan operation start process is performed. When performing the scan drive in step S205, the camera control unit 21 scans the focus lens 32 at the third scan speed V _Scan3 . Here, the third scan speed V _Scan3 is a speed slower than the first scan speed V _Scan1 at the time of still image shooting. For example, the in-focus position can be appropriately detected by a contrast detection method, and the focus lens 32 is used. It is possible to set the speed so that the image change of the photographed image by the driving of becomes a predetermined value or less. Thereby, in this embodiment, at the time of moving image shooting, it is possible to reduce the image change of the shot image by driving the focus lens 32, and it is possible to take a good-looking moving image while the scan drive is being performed. .

In step S205 as well, as in step S105 of FIG. 9, the camera control unit 21 performs wobbling driving for reciprocally driving the focus lens 32 in the optical axis direction before performing scanning driving. Further, when performing the wobbling drive in step S205, the camera control unit 21 causes the focus lens 32 to be wobbled at a predetermined second wobbling speed _VWobb2 . Note that the second wobbling speed _VWobb2 can be the same speed as the first wobbling speed _VWob1 at the time of still image shooting.

  After the scan operation is started in step S205, the process proceeds to step S206. In steps S206 to S208, the scan operation is executed in the same manner as steps S106 to S108 in FIG.

As a result of executing the scanning operation, if it is determined in step S206 that the defocus amount can be calculated by the phase difference detection method, the scanning operation is stopped and then the process proceeds to step S209, where the phase difference detection method is executed. Servo driving for driving the focus lens 32 is performed at the third servo speed V _Servo3 suitable for moving image shooting based on the defocus amount calculated by the above.

As a result of executing the scanning operation, if it is determined in step S207 that the in-focus position has been detected by the contrast detection method, the scanning operation is stopped and then the process proceeds to step S210, where the detection is performed by the contrast detection method. Focus driving is performed based on the focused position. Further, when performing the focus drive in step S210, the camera control unit 21 performs control so as to drive the focus lens 32 at the third focus speed V _Focus3 . Here, the third focusing speed V _Focus3 is a speed slower than the first focusing speed V _Focus1 at the time of still image shooting. For example, the change in the captured image due to the driving of the focus lens 32 becomes a predetermined value or less. The speed can be as follows. Accordingly, in the present embodiment, even when focus driving is performed during moving image shooting, a change in the captured image due to driving of the focus lens 32 is reduced, and a moving image with good appearance can be captured. When the focus lens 32 is driven to the in-focus position detected by the contrast detection method, the process proceeds to step S212.

  On the other hand, if it is determined in step S208 that the scan operation has been completed for the entire driveable range of the focus lens 32, the process proceeds to step S211. In step S211, 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, and therefore the scanning operation end processing is performed.

  In step S212, it is determined whether or not the focus state of the optical system has changed. For example, when the defocus amount by the phase difference detection method repeatedly calculated by the camera control unit 21 changes by a predetermined value or more, or when the defocus amount cannot be calculated, or is also repeatedly calculated by the camera control unit 21. When the focus evaluation value is changed by a predetermined value or more, it can be determined that the focus state of the optical system has changed. If it is determined that the focus state of the optical system has changed, the process returns to step S203. On the other hand, if the focus state of the optical system has not changed, a predetermined end operation, for example, a power-off operation of the camera 1 is performed. Or until the moving image shooting end operation is performed (step S213) or until the focus state of the optical system changes (step S212), the focus lens 32 is stopped at the current lens position.

  On the other hand, if it is determined in step S203 that the shutter release button has been pressed halfway, the process proceeds to step S301 in FIG. In the operation of the camera 1 shown in FIG. 12, the drive of the focus lens 32 is controlled so that the subject is focused in a short time.

  That is, first, in step S301, as in step S204 in FIG. 11, it is determined whether or not the defocus amount has been calculated by the phase difference detection method. If it is determined that the distance is possible, the process proceeds to step S306. If the defocus amount cannot be calculated, it is determined that distance measurement is impossible, and the process proceeds to step S302.

If it is determined in step S301 that the defocus amount has been calculated, the process proceeds to step S306, and the servo drive that drives the focus lens 32 to a position corresponding to the calculated defocus amount, as in step S209 in FIG. Is done. When performing servo drive in step S306, the camera control unit 21 _drives the focus lens 32 to the in-focus position at the second servo speed V _Servo2 . Here, the second servo speed V _Servo2 is slower than the first servo speed V _Servo1 during still image shooting and is _higher than the third servo speed V _Servo3 when the shutter release button is not half-pressed during moving image shooting. For example, the maximum speed among the speeds at which the drive sound of the focus lens 32 is not recorded can be set. Thereby, in this embodiment, when the shutter release button is half-pressed during moving image shooting, the driving sound of the focus lens 32 is effectively prevented from being recorded by the servo drive during moving image shooting. It is possible to reduce the time required for servo drive during shooting. In the present embodiment, the second servo speed V _Servo2 is stored in the memory _included in the lens control unit 37, and the camera control unit 21 acquires the second servo speed V _Servo2 from the lens control unit 37. Can do.

In step S306, as in step S209 in FIG. 11, the defocus amount is repeatedly calculated at a predetermined interval even after servo drive of the focus lens 32 is started. As a result, a new defocus amount is obtained. When the focus amount is calculated, the focus lens 32 is servo-driven at the second servo speed V _Servo2 based on the newly calculated defocus amount. When the focus lens 32 is driven to the in-focus position based on the defocus amount, the process proceeds to step S309.

On the other hand, if it is determined in step S301 that the defocus amount cannot be calculated, or if it is determined that the reliability of the calculated defocus amount is low, the process proceeds to step S302, and step S205 in FIG. 11 is performed. Similarly to the above, a scan operation start process is performed. When performing the scan drive in step S302, the camera control unit 21 scans and drives the focus lens 32 at the second scan speed V _Scan2 . Here, the second scan speed V _Scan2 is slower than the first scan speed V _Scan1 during still image shooting and is _higher than the third scan speed V _Scan3 when the shutter release button is not half-pressed during moving image shooting. Fast speed. In the present embodiment, the second scan speed V _Scan2 can be _set to, for example, the maximum speed among the speeds at which the focus position can be detected by the contrast detection method and the driving sound of the focus lens 32 is not recorded. Thereby, in the present embodiment, it is possible to reduce the time required for scan driving during moving image shooting while effectively preventing the drive sound of the focus lens 32 from being recorded due to scan driving during moving image shooting. . In the present embodiment, the second scan speed V _Scan2 is stored in a memory _included in the lens control unit 37, and the camera control unit 21 acquires the second scan speed V _Scan2 from the lens control unit 37. Can do.

Also in step S302, as in step S205 in FIG. 11, the camera control unit 21 performs wobbling driving that causes the focus lens 32 to reciprocate slightly in the optical axis direction before performing scanning driving. When performing the wobbling drive in step S302, the camera control unit 21 causes the focus lens 32 to perform a wobbling drive at a predetermined second wobbling speed _VWobb2 . The second wobbling speed _VWobb2 can be _set to the same speed as the first wobbling speed _VWob1 during still image shooting and the third wobbling speed _VWob3 during moving image shooting.

Then, after the scan operation is started in step S302, the process proceeds to step S303, and in steps S303 to S305, the scan operation is executed as in steps S206 to S208 of FIG. As a result of executing the scanning operation, if it is determined in step S303 that the defocus amount can be calculated by the phase difference detection method, after the scanning operation is stopped, the process proceeds to step S306, as described above. Servo driving for driving the focus lens 32 is performed at the second servo speed V _Servo2 up to a position corresponding to the defocus amount calculated by the phase difference detection method.

As a result of executing the scanning operation, if it is determined in step S304 that the in-focus position has been detected by the contrast detection method, after the scanning operation is stopped, the process proceeds to step S307 to detect by the contrast detection method. Focus driving is performed based on the focused position. When performing the focus drive in step S307, the camera control unit 21 _drives the focus lens 32 to the focus position at the second focus speed V _Focus2 . Here, the second focus speed V _Focus2 is the third focus speed that is slower than the first focus speed V _Focus1 during still image shooting and the shutter release button is not half-pressed during movie shooting. The focusing speed V _Focus3 is faster than the focusing speed V _Focus3 . For example, it can be the maximum speed among the speeds at which the driving sound of the focus lens 32 is not recorded. Thereby, in the present embodiment, it is possible to effectively prevent the drive sound of the focus lens 32 from being recorded by the focus drive at the time of moving image shooting, and to reduce the time required for the focus drive at the time of moving image shooting. Can do. In the present embodiment, the second focusing speed V _Focus2 is stored in a memory provided in the lens control unit 37, and the camera control unit 21 acquires the second focusing speed V _Focus2 from the lens control unit 37. be able to.

  On the other hand, if it is determined in step S305 that the scan operation has been completed for the entire driveable range of the focus lens 32, the process proceeds to step S308, and the scan operation is performed as in step S211 of FIG. Is completed.

In step S309, the camera control unit 21 determines whether the half-press of the shutter release button is released (the first switch SW1 is turned off). If the half-press of the shutter release button has not been released, the process proceeds to step S310, and the focus lens 32 continues until the focus state of the optical system changes (step S310) or until a predetermined end operation is performed (step S311). While waiting at the current lens position. When the focus state of the optical system has changed (step S310 = Yes), the process returns to step S301, and the second scan speed V _Scan2 , the second servo speed V _Servo2 , and the second focusing speed V _Focus2 are respectively obtained. Scan driving, servo driving, and focusing driving are repeatedly performed.

On the other hand, if the half-press of the shutter release button is released in step S309, the process returns to step S212 in FIG. 11, and the first scan speed V _Scan1 , the first servo until the shutter release button is half-pressed again. The scan drive, the servo drive, and the focus drive are repeatedly performed at the speed V _Servo1 and the first focus speed V _Focus1 , respectively.

As described above, in the present embodiment, at the time of still image shooting, the first servo speed V _{Servo1 of} servo drive and the first focus speed V _Focus1 of focus drive are _set to the maximum drive speed of the focus lens 32, for example. The focus lens 32 is driven by _setting the first scan speed V _Scan1 of the scan drive as the maximum speed among the speeds at which focus detection can be appropriately _performed by, for example, the contrast detection method, so that the focusing time at the time of still image shooting can be reduced. It can be shortened.

Further, in the present embodiment, at the time of moving image shooting, the third servo speed V _{Servo3 of} servo drive and the third focus speed V _Focus3 of focus drive are respectively _set to the first servo speed V _Servo1 and first servo speed at the time of still image shooting. By driving the focus lens 32 at a speed slower than the in-focus speed V _Focus1 , for example, a speed at which the change in the captured image by driving the focus lens 32 is equal to or less than a predetermined value, A change in the captured image due to the drive can be reduced, and thus a moving image with a good appearance can be captured even while the servo drive or the focus drive is performed. Similarly, at the time of moving image shooting, the third scan speed V _Scan3 of scan driving can be appropriately detected by a speed slower than the first scan speed V _Scan1 at the time of still image shooting, for example, a contrast detection method, In addition, by driving the focus lens 32 at such a speed that the change in the captured image due to the drive of the focus lens 32 is less than or equal to a predetermined value, the change in the captured image due to the drive of the focus lens 32 is reduced during moving image shooting. It is possible to capture a good-looking moving image while the scanning operation is being performed.

Furthermore, in the present embodiment, when the shutter release button is half-pressed during moving image shooting, the servo-driven second servo speed V _Servo2 is slower than the first servo speed V _{Servo1 and} higher than the third servo speed V _Servo3. By driving the focus lens 32 at a high speed, for example, the maximum speed at which the drive sound of the focus lens 32 is not recorded, the drive sound of the focus lens 32 is recorded by the servo drive at the time of moving image shooting. It is possible to reduce the time required for the servo drive during moving image shooting while effectively preventing the occurrence of the error. Similarly, when the shutter release button is pressed halfway during moving image shooting, the second focus speed V _Focus2 for focus drive is slower than the first focus speed V _{Focus1 and} faster than the third focus speed V _Focus3. By driving the focus lens 32 as the maximum speed among the speeds at which the drive sound of the focus lens 32 is not recorded, the drive sound of the focus lens 32 is recorded by the focus drive during movie shooting. It is possible to reduce the time required for focusing driving at the time of moving image shooting, while effectively preventing the image from moving. Further, when the shutter release button is pressed halfway during moving image shooting, the second scan speed V _Scan2 of the scan drive is _set to a speed that is _lower than the first scan speed V _{Scan1 and} higher than the third scan speed V _Scan3 , for example, The focus detection can be appropriately performed by the contrast detection method, and the focus lens 32 is scan-driven as the maximum speed at which the drive sound of the focus lens 32 is not recorded. Thus, it is possible to reduce the time required for scan driving during moving image shooting while effectively preventing the drive sound of the focus lens 32 from being recorded.

  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 scene where the scan driving, the servo driving, and the focusing driving are performed is described as an example. However, the present invention is not limited to this configuration. For example, the moving subject is detected and the detected moving subject is supported. By detecting the defocus amount to be performed in time series, the image plane position in the optical axis direction of the moving subject is predicted based on the time change of the defocus amount, and the focus lens 32 is placed at the predicted image plane position. The present invention can also be applied to predictive driving. For example, when performing predictive driving during still image shooting, the focus lens 32 may be driven at the first predicted speed _VPro1 that is the maximum drive speed of the focus lens 32, for example. Further, when predictive driving is performed at the time of moving image shooting, the focus lens 32 is moved at a speed slower than the first predicted speed _VPro1 at the time of still image shooting, for example, a change in a captured image by driving the focus lens 32 is a predetermined value or less. It is good also as a structure driven by 3rd estimated speed _VPro3 which becomes. Furthermore, when performing predictive drive when half-press operation of the shutter release button during moving image shooting is performed, a focusing lens 32, a faster rate than the third predicted velocity V _Pro3 slower than the first predicted velocity V _Pro1 For example, it may be configured to drive at the second predicted speed _VPro2 which is the maximum speed among the speeds at which the driving sound of the focus lens 32 is not recorded during moving image shooting.

  In the above-described embodiment, the driving speed of the focus lens 32 at the time of still image shooting is the image plane moving speed, and the driving speed of the focus lens 32 when the shutter release button is half-pressed at the time of moving image shooting. However, the present invention is not limited to this configuration. For example, when the focus lens 32 is driven at the maximum drive speed, the drive sound of the focus lens 32 is not recorded. The driving speed of the focus lens 32 during still image shooting and the driving speed of the focus lens 32 when the shutter release button is half-pressed during moving image shooting may be set to the same speed.

  Furthermore, in the above-described embodiment, the imaging element 22 includes the imaging pixel 221 and the focus detection pixels 222a and 222b, and the focus detection pixels 222a and 222b included in the imaging element 22 perform focus detection by the phase difference detection method. However, the present invention is not limited to this configuration, and a focus detection module for performing focus detection by the phase difference detection method may be provided independently of the image sensor 22.

  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 (8)

The first mode is set to the still image shooting or the second mode Selectable selector you shooting a movie,
A phase difference detection unit that detects a phase difference to calculate a focus position;
When moving the full Okasurenzu to calculate the focus position using the phase difference detection unit, when moving the focus lens to the focus position that is calculated using the output of the phase difference detection section When the focus lens is moved to a position where the subject is predicted to move, the focus lens is moved at a first speed when the first mode is selected by the selection unit, and the selection unit When the second mode is selected and the shooting preparation operation is performed, the focus lens is moved at a second speed slower than the first speed, and the second mode is selected by the selection unit and the shooting preparation operation is performed. And a control unit that moves the focus lens at a third speed that is slower than the second speed when the focus lens is not turned on. A selection unit capable of selecting a first mode for taking a still image or a second mode for taking a movie;
A phase difference detection unit that detects a phase difference to calculate a focus position;
When the focus lens is moved to calculate the in-focus position using the phase difference detection unit, the focus lens is moved at a first speed when the first mode is selected by the selection unit; When the second mode is selected by the selection unit and an operation for preparing for photographing is performed, the focus lens is moved at a second speed slower than the first speed, and the second mode is selected by the selection unit and the second mode is selected. A control unit that moves the focus lens at a third speed that is slower than the second speed when a shooting preparation operation is not performed,
The control unit moves the focus lens at a seventh speed when the first mode is selected by the selection unit when the focus lens is moved to a position where a subject is predicted to move, and the selection is performed. When the second mode is selected by the unit and the preparation for shooting is performed, the focus lens is moved at an eighth speed slower than the seventh speed, and the second mode is selected by the selection unit and the photographing is performed. A focus adjustment device that moves the focus lens at a ninth speed that is slower than the eighth speed when a preparation operation is not performed. The focus adjustment device according to claim 2, comprising:
The control unit moves the focus lens to the in-focus position calculated using the output of the phase difference detection unit, and moves the focus lens when the first mode is selected by the selection unit. When the second mode is selected by the selection unit and the shooting preparation operation is performed, the focus lens is moved at a fifth speed slower than the fourth speed, and the selection unit A focus adjustment device that moves the focus lens at a sixth speed that is slower than the fifth speed when the second mode is selected and the preparation for photographing is not performed. The focus adjustment device according to any one of claims 1 to 3 ,
A movement direction detection unit that determines a movement direction of the focus lens by detecting an evaluation value related to contrast when the focus lens is moved in a first direction and a second direction opposite to the first direction;
The control unit is configured to determine the speed of the focus lens when the movement direction detection unit moves the focus lens in the first direction and the second direction in order to determine a drive direction of the focus lens. When the first mode is selected by the selection unit, the second mode is selected by the selection unit and the shooting preparation operation is performed, and the second mode is selected by the selection unit and the shooting preparation is performed. Focusing device that does not change when the camera is not operated. The focus adjustment device according to any one of claims 1 to 4 , wherein:
The control unit is a focus adjustment device that drives the focus lens after the shooting preparation operation is performed. The focus adjustment device according to claim 5 , comprising:
A focus adjustment device that performs the above-mentioned preparation for shooting when the release button is half-pressed. An imaging device comprising the focus adjustment device according to any one of claims 1 to 6 . The imaging apparatus according to claim 7 , wherein
An imaging apparatus having an imaging unit including a focus detection pixel used for focus detection by a phase difference detection method and a pixel different from the focus detection pixel.

Images