JP2014095733A - Image capturing device and control method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image capturing device which performs generation of a display image and detection of phase difference using image signals read from a read-out region of an image sensor and is capable of preventing reduction in accuracy of focus detection which is done using the detected phase difference.SOLUTION: An image capturing device includes an image sensor with pixel units, each having a plurality of photo-electric conversion sections for one microlens. The image capturing device defines a read-out region from the pixel units, detects phase difference from image signals read from the region, and outputs reliability of the phase difference. The image capturing device assesses validity of the phase difference detection using the phase difference reliability. If the phase difference detection is valid, the image capturing device carries out a focus adjustment process using the detected phase difference and, if the phase difference detection is invalid, focuses a lens, which forms an optical image of an object on the image sensor, in accordance with the outputted phase difference reliability.

Description

  The present invention relates to an imaging apparatus and a method for controlling the imaging apparatus.

  In the imaging device, a technique for performing phase difference type focus detection by dividing a photodiode (PD) focused by one microlens in one pixel has been proposed. Patent Document 1 discloses an imaging device in which a photodiode in one pixel is divided into two, and each of the divided photodiodes is configured to receive light from different pupil planes of the imaging lens. To do. This imaging device performs focus detection with an imaging lens by comparing the outputs of two photodiodes.

  In addition, an imaging apparatus has been proposed that has an image sensor that can read a specific area and has a function of zooming to a telephoto side without using a zoom lens by reading an area smaller than the entire area of the image sensor. Patent Document 2 discloses an imaging apparatus that realizes a zoom range wider than that performed by only one by controlling a combination of electronic zoom and optical zoom.

JP 2001-083407 A JP 2002-314868 A

  Applying the technique of Patent Document 1 to the technique of Patent Document 2 to generate a zoom display image by reading a specific region of the image sensor and using a plurality of PDs included in one pixel An imaging apparatus (hereinafter, referred to as an imaging apparatus A) that performs the focus detection can be considered. However, the imaging apparatus A has the following problems.

  FIG. 9 is a diagram for explaining operation processing of the imaging apparatus A. When the left and right PDs included in one pixel of the imaging apparatus are two, two images, a left image and a right image, are obtained from each PD. FIG. 9B is a diagram showing left image line data and right image line data.

  Here, when the imaging apparatus A reads out the entire angle of view of the imaging device as shown in FIG. 9A, line data from coordinates (X1, Y) to (X4, Y) on the imaging device is used. Thus, the phase difference can be calculated. However, when the imaging apparatus A reads a specific area of the imaging element as shown in FIG. 9C, the area that can be used for calculating the phase difference is limited to the range from (X2, Y) to (X3, Y). As a result, the focus detection accuracy decreases.

  The present invention is an image pickup apparatus that generates a display image and detects a phase difference based on an image signal read from a read area of an image pickup element, and prevents a decrease in focus detection accuracy based on the detected phase difference. An object is to provide an imaging device.

  An imaging apparatus according to an embodiment of the present invention includes a plurality of photoelectric conversion units that generate an image signal by photoelectrically converting a light beam that has passed through different regions of an exit pupil of an imaging optical system with respect to one microlens. An image sensor including a pixel unit, a setting unit that sets a reading region that is a region for reading an image signal from the pixel unit, a left image signal and a right image signal included in the image signal read from the reading region, Detecting means for performing phase difference detection processing for outputting the reliability of the phase difference, and determining whether the detection of the phase difference is successful based on the output reliability of the phase difference And a lens for performing focus adjustment processing based on the detected phase difference when it is determined that the detection of the phase difference is successful, and a lens for forming an optical image of a subject on the imaging device. Drive And a driving unit that instructs the driving unit to squeeze the lens according to the reliability of the phase difference output by the detecting unit when it is determined that the detection of the phase difference has failed. Is provided.

  According to the imaging apparatus of the present invention, based on the image signal read from the readout area of the imaging device, a display image (for example, an image for zoom display) is generated and a phase difference is detected. It is possible to prevent a decrease in the accuracy of the focus detection based on it.

It is a figure which shows the structural example of the imaging device of this embodiment. It is a figure which shows the structural example of an image pick-up element roughly. It is a figure which shows the example of a pixel array. It is the conceptual diagram showing a mode that the light beam which came out of the exit pupil of the imaging lens injects into an image pick-up element. It is a figure which shows the structural example of a video signal processing part. 3 is a flowchart illustrating an example of operation processing of the imaging apparatus according to the first embodiment. It is a figure explaining the setting of a read-out area | region. 10 is a flowchart illustrating an example of operation processing of the imaging apparatus according to the second embodiment. It is a figure explaining the operation processing of an imaging device.

  FIG. 1 is a diagram illustrating a configuration example of an imaging apparatus according to the present embodiment. Among the components included in the imaging apparatus 100, the power supply 100 supplies power to each circuit in the imaging apparatus 100. The card slot 172 is configured such that a memory card (detachable recording medium) 173 can be inserted. With the memory card 173 inserted into the card slot 172, the memory card 173 is electrically connected to the card input / output unit 171. In this embodiment, the memory card 173 is employed as the recording medium, but other recording media such as a hard disk, an optical disk, a magneto-optical disk, a magnetic disk, and other solid-state memories may be used.

  The imaging lens 101 forms an optical image of the subject on the imaging element 103. The lens driving unit 141 drives the imaging lens 101 to execute zoom control, focus control, aperture control, and the like. The mechanical shutter 102 is driven by the shutter control unit 142 and executes exposure control.

  The image sensor 103 is a photoelectric conversion means configured by a CMOS image sensor or the like. The imaging element 103 photoelectrically converts a subject image formed by an imaging optical system having an imaging lens 101 and a shutter 102 and outputs an image signal.

  FIG. 2 is a diagram schematically illustrating a configuration example of an imaging element applied by the imaging apparatus of the present embodiment. FIG. 2A shows the overall configuration of the image sensor. The image sensor 103 includes a pixel array 201, a vertical selection circuit 202 that selects a row in the pixel array 201, and a horizontal selection circuit 204 that selects a column in the pixel array 201. The readout circuit 203 reads out the signal of the pixel portion selected by the vertical selection circuit 202 among the pixel portions in the pixel array 201. The reading circuit 203 includes a memory for storing signals, a gain amplifier, an A (Analog) / D (Digital) converter, and the like for each column.

  A serial interface (SI) unit 205 determines an operation mode of each circuit according to an instruction from the CPU 131. The vertical selection circuit 202 sequentially selects a plurality of rows in the pixel array 201 and extracts pixel signals to the readout circuit 203. The horizontal selection circuit 204 sequentially selects a plurality of pixel signals read by the reading circuit 303 for each column. By appropriately changing the operations of the vertical selection circuit 202 and the horizontal selection circuit 204, reading of a specific area can be realized. In addition to the components shown in FIG. 2, the image sensor 103 includes, for example, a timing generator that provides a timing signal to the vertical selection circuit 202, the horizontal selection circuit 204, the readout circuit 203, and a control circuit. Detailed description thereof will be omitted.

  FIG. 2B illustrates a configuration example of a pixel portion of the image sensor 103. A pixel portion 300 illustrated in FIG. 2B includes a microlens 301 as an optical element and a plurality of photodiodes (hereinafter abbreviated as PD) 302a to 302d as light receiving elements. The PD functions as a photoelectric conversion unit that receives a light beam and photoelectrically converts the light beam to generate an image signal. Note that in the example illustrated in FIG. 2B, the number of PDs included in one pixel portion is four, but the number of PDs may be an arbitrary number of two or more. The pixel unit includes, in addition to the illustrated components, for example, a pixel amplification amplifier for reading a PD signal to the reading circuit 203, a selection switch for selecting a row, a reset switch for resetting the PD signal, and the like. .

  PD 302a and PD 302c photoelectrically convert the received light beam and output a left image signal. PD 302b and PD 302d photoelectrically convert the received light beam and output a right image signal. That is, among a plurality of PDs included in one pixel unit, an image signal output by the right PD is a right image signal, and an image signal output by the left PD is a left image signal.

  When the imaging apparatus according to the present embodiment is configured to allow the user to view a stereoscopic image, the image data corresponding to the left image signal functions as left-eye image data that the user views with the left eye. The image data corresponding to the right image signal functions as right-eye image data that the user views with the right eye. If the imaging apparatus 100 allows the user to appreciate the left-eye image data with the left eye and causes the user to appreciate the right-eye image data with the left eye, the user can appreciate the stereoscopic image. The imaging apparatus may select and add the outputs of a plurality of PDs. For example, the imaging apparatus may add the PD outputs of PD 302a and PD 302c, PD 302b and PD 302d, and obtain two outputs. The pixel unit 300 includes, for example, a pixel amplification amplifier that extracts a PD signal to the readout circuit 303, a row selection switch, a PD signal reset switch, and the like in addition to the illustrated components.

  FIG. 3 is a diagram illustrating an example of a pixel array. In order to provide a two-dimensional image, the pixel array 201 is configured by arranging a plurality of N pixel portions in the horizontal direction and a plurality of M pixel portions in the vertical direction as shown in FIG. Each pixel unit 300 of the pixel array 201 has a color filter. In this example, odd rows are repetitions of red (R) and green (G) color filters, and even rows are repetitions of green (G) and blue (B) color filters. That is, the pixel units included in the pixel array 301 are arranged according to a predetermined pixel arrangement (in this example, a Bayer arrangement).

  Next, light reception of the image sensor having the pixel configuration shown in FIG. 3 will be described. FIG. 4 is a conceptual diagram illustrating a state in which a light beam emitted from the exit pupil of the photographing lens enters the image sensor. Reference numeral 501 indicates a cross section of three pixel arrays. Each pixel array includes a microlens 502, a color filter 503, and PDs 504 and 505. The PD 504 corresponds to the PD 302a in FIG. The PD 505 corresponds to the PD 302b in FIG.

  Reference numeral 506 denotes an exit pupil of the photographing lens. In this example, the center of the light beam emitted from the exit pupil 506 is defined as the optical axis 509 for the pixel portion having the microlens 502. Light emitted from the exit pupil 506 is incident on the image sensor 103 around the optical axis 509. Reference numerals 507 and 508 denote partial areas of the exit pupil of the photographing lens. The partial areas 507 and 508 are different areas obtained by dividing the exit pupil of the imaging optical system.

  Light rays 510 and 511 are the outermost light rays of the light passing through the partial region 507. Light rays 512 and 513 are the outermost peripheral light rays of the light passing through the partial region 508. Out of the light beams emitted from the exit pupil, the upper light beam is incident on the PD 505 and the lower light beam is incident on the PD 504 with the optical axis 509 as a boundary. That is, the PD 504 and the PD 505 each have a characteristic of receiving light in a different region with respect to the exit pupil of the photographing lens.

  Taking advantage of this characteristic, the imaging apparatus 100 can acquire at least two images having parallax. For example, the imaging apparatus 100 acquires a left image signal as a first line from a plurality of left PDs and acquires a right image signal as a second line from a plurality of right PDs in an area in the pixel unit. The imaging apparatus 100 detects the phase difference between the two image signals to realize phase difference AF (autofocus).

  From the above description, the imaging element 103 is a pixel having a plurality of PDs that generate an image signal by photoelectrically converting light beams that have passed through different areas of the exit pupil of the imaging optical system with respect to one microlens. This is an image sensor in which the units are arranged in the horizontal direction and the vertical direction.

  Returning to FIG. 1, the video signal processing unit 121 generates image data for display based on the image signal output from the image sensor 103.

  FIG. 5 is a diagram illustrating a configuration example of the video signal processing unit. The video signal processing unit 121 includes a phase difference detection unit 601, an image addition unit 602, a trimming processing unit 603, and a development processing unit 604. The phase difference detection unit 601 detects a phase difference between the left image signal and the right image signal output from the readout region of the pixel unit included in the image sensor 103 and outputs the detection result to the memory 132. The reading area is an area for reading an image signal from the pixel portion.

  The phase difference detection unit 601 outputs the reliability of the calculated phase difference. The phase difference detection unit 601 may output the detection result to the internal memory of the phase difference detection unit 601 instead of the memory 132. That is, the phase difference detection unit 601 detects the phase difference between the left image signal and the right image signal included in the image signal read from the reading area, and outputs the detected phase difference and the reliability of the phase difference. It functions as a detection means. Specifically, the phase difference detection unit 601 detects the phase difference between the left image signal and the right image signal included in the image signal for one horizontal line in the set readout region. The reliability corresponds to the similarity between the left image signal and the right image signal. The reliability is higher as the similarity between the left image signal and the right image signal is higher.

  The image addition unit 602 performs addition synthesis of the right image signal and the left image signal and outputs the result as one image data. The trimming processing unit 603 executes processing (trimming processing) for cutting out part of the image data output from the image adding unit 602. The development processing unit 604 performs processing such as white balance, color interpolation, color correction, γ conversion, edge enhancement, resolution conversion, and image compression on the trimming processing result (digital image data) output from the trimming processing unit 603. To do. Thereby, image data for display is generated.

  Returning to FIG. 1, the memory 132 stores display image data output from the video signal processing unit 121. The memory 132 temporarily stores data when the CPU 105 performs various processes. The timing generator 143 provides timing to the image sensor 103 and the video signal processing circuit 141. To the bus 150, a lens driving unit 141, a shutter driving unit 142, an image sensor 103, a timing generator 143, a video signal processing unit 121, a CPU 131, a power supply 110, a memory 132, and a display control device 151 are connected. The bus 150 also includes a main switch 161, a first release switch 162, a second release switch 163, a live view start / end button 164, an AF start / end button 165, an up / down / left / right selection button 166, an enter button 167, a card input. An output unit 171 is connected.

  The CPU 131 controls the entire imaging apparatus 100. For example, the CPU 131 controls the operation timing of the image signal reading process of the image sensor 103, the video signal processing unit 121, and the memory 132. The display control device 151 drives and controls the TFT 152 made of a liquid crystal display element, the VIDEO output terminal 153, and the HDMI terminal. Further, the display control device 151 outputs the display image data stored in the memory 132 to the display device in accordance with an instruction from the CPU 131. The display image data area in the memory 132 is referred to as VRAM. The display control device 151 outputs the VRAM to the TFT 152, whereby the display image is updated (display update processing is executed).

  When the user turns on the main switch 161, the CPU 131 executes a predetermined program. When the user turns off the main switch 161, the CPU 131 executes a predetermined program and puts the camera into a standby mode.

  The first release switch 162 is turned on at the first stroke (half-pressed state) of the release button. The second release switch 163 is turned on by the second stroke (fully pressed state) of the release button. In addition, the CPU 131 performs control according to pressing of the up / down / left / right selection button 166 and the setting button 167 and the operation state of the imaging apparatus 100. The user can specify a subject to be autofocused with the up / down / left / right selection buttons 166 during live view. The user can switch and set the live view shooting to either the normal mode or the zoom mode by performing selection and setting in the graphical user interface using the up / down / left / right selection button 166 and the setting button 167. Live view shooting when the zoom mode is set is described as zoom live view shooting.

  During zoom live view shooting, an image signal read from a predetermined reading area of the image sensor 103 is input to the video signal processing unit 121 to the video signal processing unit 121. Further, the CPU 131 enlarges the image data output from the video signal processing unit 121 in accordance with a predetermined zoom magnification to obtain display image data.

  When the user presses the live view start / end button 164, the CPU 131 periodically captures image data from the image sensor 103 (for example, 30 times per second) and arranges the image data in the VRAM. As a result, an image captured from the image sensor 103 can be displayed in real time. When the user presses the live view start / end button 164 while the live view is operating, the live view ends. When the user presses the AF start / end button 165, the imaging apparatus 100 starts an autofocus operation. That is, the AF start / end button 165 functions as an instruction unit that instructs the start of execution of the automatic focus adjustment process. The control method of the imaging apparatus of the present embodiment is realized by the function of the processing unit included in the imaging apparatus 100 illustrated in FIG.

Example 1
FIG. 6 is a flowchart illustrating an example of operation processing of the imaging apparatus according to the first embodiment. The CPU 131 detects that the live view start / end button 164 has been pressed, and starts zoom live view shooting (step S100). Subsequently, the CPU 131 functions as a setting unit that sets a reading area (step S101).

  FIG. 7 is a diagram for explaining the setting of the readout area. The left image signal and the right image signal shown in FIG. 7A are the left image signal and the right image signal when the reading area is set in step S101. In the example shown in FIG. 7A, the phase difference between the left image signal and the right image signal is large, and the focus is not achieved.

  A region R1 surrounded by a thick line in FIG. 7A is a read region set in step S101. The readout region R1 is a region corresponding to a section from X2 to X3 in the horizontal direction on the image sensor. The display area is an area for generating display data. In this embodiment, the display area coincides with the reading area R1. Of course, the display area may be set to an area included in the readout area R1 and smaller than the readout area R1.

  Next, the CPU 131 determines whether or not the AF start / end button 165 is turned on (step S102). If the AF start / end button 165 is not ON, the process returns to step S102 again.

  The AF start / end button 165 functions as an instruction means for instructing the start of the focus adjustment process. When this button is turned on, it means that the execution start of the automatic focus adjustment process has been instructed. Therefore, when the AF start / end button 165 is turned on, the phase difference detection unit 601 detects the phase difference between the left image signal and the right image signal read from the read area set in step S101, and The phase difference and its reliability are stored in the memory 132 as an output result. Then, the process proceeds to step S103.

  In step S103, the CPU 131 reads the output result of the phase difference detection unit 601 from the memory 132 (step S103). The output result of the phase difference detection unit 601 includes the phase difference obtained from the line data in the section (X2, Y) to (X3, Y) in FIG.

  Next, the CPU 131 determines whether the phase difference has been successfully detected based on the reliability of the phase difference included in the output result of the phase difference detection unit 601 (step S104). When the reliability of the phase difference exceeds the threshold, the CPU 131 determines that the phase difference has been successfully detected. Further, when the reliability of the phase difference is equal to or less than the threshold, the CPU 131 determines that the detection of the phase difference has failed. If the CPU 131 determines that the phase difference has been successfully detected, the process proceeds to step S105. Then, the CPU 131 calculates the focus control amount of the imaging lens 101 based on the detected phase difference, and performs focus control through the lens driving unit 141 (step S105). That is, the CPU 131 functions as an adjustment unit that executes the focus adjustment process based on the detected phase difference.

  When the focus control is completed, the process proceeds to step S106. Then, the CPU 131 displays the completion of focusing on the TFT 152 via the display control device 151 (step S106), and proceeds to step S114.

  If the CPU 131 determines that the phase difference detection has failed, the process proceeds to step S107. Then, the CPU 131 determines the lens aperture amount to be a predetermined aperture amount and sets it in the lens driving unit 141. The CPU 131 holds the aperture value before setting the aperture amount in the memory 132. The CPU 131 may set the aperture amount to one level or two levels. However, the CPU 131 does not determine a diaphragm amount that affects the accuracy of the phase difference detection unit 601 by narrowing the imaging lens 101. This is because if the imaging lens 101 is made too narrow, the image becomes too dark and the accuracy of the phase difference detection unit 601 decreases. Therefore, the CPU 131 sets the lens aperture amount in a range in which the reliability of the phase difference output by the phase difference detection process does not fall below the threshold value.

  Next, in step S108, the lens driving unit 141 stops the imaging lens 101 with the aperture amount determined in step S107 (performs lens aperture driving). That is, the CPU 131 functions as a control unit that instructs the lens driving unit 141 to narrow down the imaging lens 101 according to the reliability of the output phase difference. Then, the phase difference detection unit 601 detects the phase difference based on the image signal read from the reading area after driving the lens diaphragm in step S108, outputs the reliability of the phase difference, and outputs the output result to the memory 132. (Step S108). That is, the phase difference detection unit 601 detects the phase difference again in a state where the imaging lens 101 is stopped, and re-outputs the reliability of the phase difference. Then, the CPU 131 reads out the output result of the phase difference detection unit 601 from the memory 132.

  By performing lens aperture driving in step S108, the phase difference between the left image signal and the right image signal from the readout region becomes small as shown in FIG. 7B. That is, when the lens is squeezed, the depth of field is deepened and the focus is slightly adjusted. Thereby, the reliability of the phase difference is increased, and the detection accuracy of the phase difference is increased.

  Returning to FIG. 6, the CPU 131 resets the aperture value stored in the memory in step S <b> 107 in the lens driving unit 141. That is, the CPU 131 returns the lens aperture value to the aperture value before the phase difference reliability is output again. In step S111, the lens driving unit 141 drives the imaging lens 101 to the aperture value set in step S110.

  Next, based on the output result of the phase difference detection unit 601 read out in step S109, the CPU 131 determines whether the phase difference has been successfully detected by the same method as the determination process in step S104 (step S112). . If the phase difference is successfully detected, the process proceeds to step S105. If the phase difference detection fails, the process proceeds to step S113.

  If it is determined in step S113 that the phase difference has been successfully detected, the process proceeds to step S105. If it is determined in step S113 that the phase difference detection has failed, the process proceeds to step S114. Then, the CPU 131 performs an out-of-focus display indicating that focusing cannot be performed on the TFT 152 through the display control device 151 (step S114), and the process proceeds to step S115.

  In step S115, the CPU 131 determines whether or not the AF start / end button 165 is turned off (step S115). If the AF start / end button 165 is not OFF, the process returns to step S115. If the AF start / end button 165 is turned off, the process proceeds to step S116. Then, the CPU 131 cancels the display (focus completion display or non-focus display) displayed on the TFT 152 (step S116) and returns to step S102.

  In this embodiment, after detecting the phase difference in step S109, the lens aperture is returned to the original in steps S110 and S111, and then the focus control in step S105 is performed. Of course, after performing the focus control in step S105, the lens aperture amount in steps S110 and S111 may be restored.

  According to the image pickup apparatus of the first embodiment, it is possible to realize an autofocus operation while ensuring the accuracy of detecting a phase difference when detecting a phase difference in a live view with partial reading.

(Example 2)
FIG. 8 is a flowchart illustrating an example of operation processing of the imaging apparatus according to the second embodiment. In the second embodiment, the CPU 131 performs the phase difference detection process (step S202) when the read area setting process (step S201) is performed. That is, unlike the imaging device of the first embodiment, the imaging device of the second embodiment performs the phase difference detection process without being triggered by the AF start / end button 165 being turned on.

  Steps S200, S201, S202, S203, and S204 in FIG. 8 are the same as steps S100, S101, S103, S104, and S105 in FIG. 6, respectively. Further, steps S205, S206, S207, S208, S209, and S210 in FIG. 8 are the same as steps S107, S108, S109, S110, S111, and S112, respectively, in FIG. In addition, after the process of step S204, it returns to step S202. If it is determined in step S211 that the phase difference detection has failed, the process returns to step S202.

  According to the imaging apparatus of the second embodiment, it is possible to realize continuous autofocus operation while ensuring the phase difference detection accuracy when detecting the phase difference in the live view with partial reading. .

(Other examples)
The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed. In this case, the program and the storage medium storing the program constitute the present invention.

DESCRIPTION OF SYMBOLS 100 Imaging device 103 Image pick-up element 131 CPU

Claims (7)

An imaging device including a pixel unit having a plurality of photoelectric conversion units that photoelectrically convert light beams that have passed through different regions divided by the exit pupil of the imaging optical system with respect to one microlens;
Setting means for setting a reading area which is an area for reading an image signal from the pixel unit;
Detecting means for detecting a phase difference between the left image signal and the right image signal included in the image signal read from the reading region, and outputting the reliability of the phase difference;
Determination means for determining whether the detection of the phase difference is successful based on the reliability of the output phase difference;
Adjusting means for executing a focus adjustment process based on the detected phase difference when it is determined that the detection of the phase difference is successful;
Driving means for driving a lens that forms an optical image of a subject on the image sensor;
Control means for instructing the drive means to squeeze the lens according to the reliability of the phase difference output by the detection means when it is determined that the detection of the phase difference has failed. An imaging device. The determination unit determines that the detection of the phase difference is successful when the reliability of the phase difference exceeds a threshold value, and fails to detect the phase difference when the reliability of the phase difference is equal to or less than the threshold value. The image pickup apparatus according to claim 1, wherein the image pickup apparatus is determined to have performed. 3. The control unit according to claim 1, wherein the control unit sets the aperture amount of the lens by the lens driving unit within a range in which the reliability of the phase difference output from the detection unit does not fall below the threshold value. The imaging device described. The detection means performs the phase difference detection process again in a state where the lens is narrowed by the lens driving means, and re-outputs the reliability of the phase difference,
After the reliability of the phase difference is re-output by the detection means, the control means returns the aperture value of the lens to the aperture value before the reliability of the phase difference is re-output. The imaging device according to any one of claims 1 to 3. Instructing means for instructing the start of the focus adjustment process,
The detection means performs the phase difference detection process and outputs the reliability of the phase difference when the instruction means instructs the start of a focus adjustment process. The imaging device according to any one of the above. The detection means stores the output phase difference and the reliability of the phase difference in a storage means,
6. The determination unit according to claim 1, wherein the determination unit determines whether the detection of the phase difference is successful based on the reliability of the phase difference stored in the storage unit. The imaging device described. An imaging device including a pixel unit having a plurality of photoelectric conversion units that photoelectrically convert light beams that have passed through different regions divided by the exit pupil of the imaging optical system with respect to one microlens, and a subject A control method for an imaging apparatus comprising: a driving unit that drives a lens that forms an optical image on the imaging element;
A setting step of setting a reading area which is an area for reading an image signal from the pixel unit;
A detection step of detecting the phase difference between the left image signal and the right image signal included in the image signal read from the reading region and outputting the reliability of the phase difference;
A determination step of determining whether the phase difference has been successfully detected based on the reliability of the output phase difference;
An adjustment step of performing a focus adjustment process based on the detected phase difference when it is determined that the detection of the phase difference is successful;
A control step of instructing the driving means to squeeze the lens according to the reliability of the phase difference output in the detection step when it is determined that the detection of the phase difference has failed. A method for controlling the imaging apparatus.

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