JP2013218152A - Imaging device and control method of the same - Google Patents

Abstract

An image pickup apparatus that generates display image data and detects a phase difference based on an image signal read from a read area of an image sensor, and prevents a decrease in focus detection accuracy based on the detected phase difference. An imaging device is provided.
An imaging device includes an imaging device including a pixel unit having a plurality of photoelectric conversion units that photoelectrically convert a light beam that has passed through different regions of an exit pupil of an imaging optical system with respect to a microlens to generate an image signal. Prepare. The imaging apparatus sets an image signal readout region and controls display / update processing of display image data generated based on the image signal. The imaging apparatus detects the phase difference between the left image signal and the right image signal read from the reading area, outputs the reliability, and determines whether the phase difference is detected based on the reliability. When the imaging device fails to detect the phase difference, the imaging device updates the readout region so that the output reliability is increased.
[Selection] Figure 1

Description

  The present invention relates to an imaging apparatus and a control method thereof.

  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 technology of Patent Literature 1 to the technology of Patent Literature 2 to read out a specific area of the image sensor and generate display image data while 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 display image data and detects a phase difference based on an image signal read from a read area of an image pickup device, and prevents a decrease in focus detection accuracy based on the detected phase difference. An object of the present invention is to provide an imaging apparatus that performs the above-described process.

  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 reads an image signal from the pixel unit, and display image data based on the image signal read from the set reading region. Generating means for generating display data, display control means for controlling display processing of the display image data on the image display means and update processing of the displayed display image data, and an image signal read from the read area A detection means for detecting a phase difference between the left image signal and the right image signal included, and outputting the detected phase difference and the reliability of the phase difference; and when the reliability of the phase difference exceeds a threshold value It is determined that the detection of the phase difference is successful, and when the reliability of the phase difference is less than or equal to a threshold value, a determination unit that determines that the detection of the phase difference has failed, and a determination that the detection of the phase difference is successful And 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 has failed, the setting unit updates the read area so that the reliability of the output phase difference is increased.

  According to the image pickup apparatus of the present invention, display image data is generated and a phase difference is detected based on an image signal read from the read area of the image pickup device, and the accuracy of focus detection based on the detected phase difference is reduced. Can be prevented.

It is a figure which shows the structural example of the imaging device of this embodiment. It is a figure showing roughly the example of composition of the image sensor which an imaging device applies. 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 imaging device A.

  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 302 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 301 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 301 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. Then, the imaging apparatus 100 detects the phase difference between the two image signals to realize the phase difference AF.

  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 display image data 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, display image data 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). That is, the CPU 131 and the display control device 151 function as display control means for controlling display processing of display image data on the image display means and update processing of the displayed display image data.

  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.

  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).

  The CPU 131 functions as a setting unit that sets a reading area (step S101). When the reading area is set, the CPU 131 and the video signal processing unit 121 function as a generating unit that generates display image data based on the image signal read from the reading area.

  FIG. 7 is a diagram for explaining the setting of the readout area. A region R1 surrounded by a thick line in FIG. 7A is a read region set in step S101. In the example shown in FIG. 7A, the CPU 131 sets the read area to R1. The readout region R1 is a region corresponding to a section from X2 to X3 in the horizontal direction and from Y4 to Y1 in the vertical direction on the image sensor. In FIG. 7A, the reading area R1 and the display area D coincide with each other, but the reading area and the display area do not necessarily coincide with each other as long as the display area is included in the reading area. In FIG. 7A, the AF area Q has a section from Y3 to Y2 in the vertical direction. Y is the vertical center coordinate of the AF area Q set by the user.

  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.

  When the AF start / end button 165 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 through the display control device 151 (step S106), and the process proceeds to step S115.

  If the CPU 131 determines that the phase difference detection has failed, the process proceeds to step S107. Then, the display control device 151 stops outputting the VRAM to the TFT 152, and stops the display update process (step S107).

  Next, the CPU 131 calculates a read area (step S108). In this example, in order to facilitate the phase difference detection, the CPU 131 determines the reading area so as to be wider in the horizontal direction than the reading area set in step S101. In other words, the CPU 131 widens the readout area in the horizontal direction so that the reliability of the phase difference output from the phase difference detection unit 601 is increased based on the image signal from the readout area. This makes it easier to determine that the phase difference has been successfully detected.

  On the other hand, if the horizontal direction of the read area is expanded, the amount of data to be captured increases, so the read time increases and the time until the phase difference can be detected also increases. Accordingly, the CPU 131 reduces the amount of data in the vertical direction of the read area so as not to increase the time until the phase difference can be detected.

  FIG. 7B shows the read area calculated in step S108 of FIG. For example, the CPU 131 calculates the reading area R2. As shown in FIG. 7B, the horizontal section of the readout region R2 is a section from X1 to X4. In addition, the vertical section of the readout region R2 is a section from Y3 to Y2. The section in the vertical direction of the reading area R2 includes the section in the vertical direction of the AF area Q with the coordinate Y as the center. In the example shown in FIG. 7B, the vertical section of the readout area R2 matches the vertical section of the AF area Q.

The CPU 131 may calculate the number of lines in the vertical section of the readout region R2 (number of readable vertical lines YC) based on the performance of the image sensor 103 as follows. If the time for reading one line from the image sensor 103 to X1 to X4 is Tx [s] and the read rate is Fx [s], the CPU 131 calculates the number YC of readable vertical lines based on the following equation.
Number of readable vertical lines YC = Fx / Tx

  For example, the time Tx for reading one line from the section from X1 to X4 is 150 [us]. Further, the read rate Fx is 33.3 [ms] when reading is performed 30 times per second. Therefore, 220 [lines] is calculated as the number YC of readable vertical lines. That is, the CPU 131 determines the vertical size of the reading area based on the reading speed of the image signal from the pixel unit.

  Returning to FIG. 7, the CPU 131 sets the read area calculated in step S <b> 108. As a result, the read area is updated to the read area calculated in step S108 (step S109). The read area after the update is the read area R2 in the example shown in FIG. As shown in FIGS. 7A and 7B, the vertical section of the readout region R2 is narrower than the vertical section of the display region D. Therefore, the imaging apparatus 100 cannot display the read image, so the display update process is stopped in step S107 described above, and the image captured in step S109 is not output to the TFT 152.

  Next, the CPU 131 reads the output result of the phase difference detection unit 601 from the memory 132 (step S110). The CPU 131 returns the read area set in step S109 to the read area before update (step S111). Subsequently, the CPU 131 starts the display update process that has been stopped (step S112). Thereby, the display control device 151 outputs the VRAM to the TFT 152.

  Next, the CPU 131 determines whether the phase difference has been successfully detected based on the output result of the phase difference detection unit 601 acquired in step S109 (step S113). If the CPU 131 fails to detect the phase difference, the process proceeds to step S113. 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 S114.

  If the CPU 131 has successfully detected the phase difference, the process proceeds to step S105. The CPU 131 executes focus control (step S105). Subsequently, the CPU 131 performs a focusing completion display indicating that focusing has been performed on the TFT 152 via the display control device 151 (step S106), 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 the imaging apparatus according to the first embodiment, when the detection of the phase difference fails, the readout area of the pixel unit is changed and set so that the detection of the phase difference is easy to succeed. Therefore, according to the image pickup apparatus of the first embodiment, display image data is generated and a phase difference is detected based on an image signal read from the read area of the image pickup device, and focus detection based on the detected phase difference is performed. A reduction in accuracy can be prevented. For example, according to the image pickup apparatus of the first embodiment, it is possible to realize the automatic focus adjustment operation while ensuring the detection accuracy of the phase difference during zoom live view shooting.

  FIG. 8 is a flowchart illustrating an example of operation processing of the imaging apparatus according to the second embodiment. In the imaging apparatus according to the first embodiment, the CPU 131 performs the phase difference detection process when the AF start / end button 165 is turned on. However, the imaging apparatus according to the second embodiment indicates that the readout area is set. The phase difference detection process is executed as an opportunity.

  Steps S200, S201, S202, S203, and S204 in FIG. 8 are the same as steps S100, S101, S103, S104, and S105 in FIG. After the focus control in step S204, the process returns to step S202.

  Steps S205 to S210 are the same as steps S107 to S113 in FIG. If the phase difference detection fails as a result of the determination process in step S210, the process returns to step S202. If the phase difference detection is successful, the process proceeds to step S204.

  According to the imaging apparatus of the second embodiment, for example, a continuous automatic focus adjustment operation can be realized while ensuring the detection accuracy of the phase difference during zoom live view shooting.

(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 (6)

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;
Generating means for generating display image data based on the image signal read from the set read area;
Display control means for controlling display processing of the display image data on the image display means and update processing of the displayed display image data;
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 readout region, and outputting the detected phase difference and the reliability of the phase difference;
Judgment that the detection of the phase difference is successful when the reliability of the phase difference exceeds a threshold value, and that the detection of the phase difference is unsuccessful when the reliability of the phase difference is equal to or less than the threshold value. Means,
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;
The setting device updates the readout region so that the reliability of the output phase difference is increased when it is determined that the detection of the phase difference has failed. The pixel units included in the imaging device are arranged in a horizontal direction and a vertical direction,
The detection means detects a phase difference between the left image signal and the right image signal included in an image signal for one horizontal line of the set readout region,
The setting means updates the set readout area to a readout area that is wider in the horizontal direction than the readout area and narrow in the vertical direction when it is determined that the detection of the phase difference has failed. The imaging apparatus according to claim 1, wherein the imaging apparatus is characterized. 3. The imaging according to claim 1, wherein the setting unit determines the vertical size of the readout region after the update based on a readout speed of an image signal from the pixel unit. apparatus. The display control means stops the update processing of the display image data displayed on the image display means when it is determined that the detection of the phase difference has failed. The imaging device according to any one of the above. An instruction means for instructing the start of execution of the automatic focus adjustment processing;
5. The detection unit according to claim 1, wherein the detection unit starts detection of the phase difference in response to an instruction to start execution of the automatic focus adjustment process by the instruction unit. The imaging device described. An imaging apparatus including 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 an exit pupil of an imaging optical system with respect to one microlens. Control method,
A setting step of setting a reading area which is an area for reading an image signal from the pixel unit;
A generation step of generating display image data based on the image signal read from the read area;
A display control step for controlling display processing of the display image data on the image display means and update processing of the displayed display image data;
A detection step of detecting a phase difference between the left image signal and the right image signal included in the image signal read from the set readout region, and outputting the detected phase difference and the reliability of the phase difference;
Determining that the detection of the phase difference has succeeded when the reliability of the phase difference exceeds a threshold value, and determining that the detection of the phase difference has failed when the reliability of the phase difference is equal to or less than the threshold value; When,
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;
An update step of updating the read area set in the setting step so that the reliability of the output phase difference is increased when it is determined that the detection of the phase difference has failed. A method for controlling the imaging apparatus.

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