Imaging device and readout control method

Abstract

To provide an imaging device etc. that can realize highly accurate subject tracking when imaging at a normal frame rate, and can continue AF processing while suppressing power consumption when imaging at a frame rate faster than the normal frame rate. [Solution] The imaging device includes an imaging element in which pixels each including a first photoelectric conversion unit and a second photoelectric conversion unit are arranged, and a read control unit that performs a first read control when a first mode is selected, in which the charges of the first photoelectric conversion unit and the second photoelectric conversion unit are separately AD converted to generate a pixel signal, and when a second mode in which a high frame rate is set is selected, performs a second read control when a first pixel is discretely set, in which the charges of the first photoelectric conversion unit and the second photoelectric conversion unit are separately AD converted to generate a first pixel signal, and when a second pixel that is not the first pixel is discretely set, performs a second read control when the charges of the first photoelectric conversion unit and the second photoelectric conversion unit are added together and then AD converted to generate a second pixel signal.

Description

[Technical Field]

[0001] The present invention relates to an imaging device and a readout control method for reading out pixel signals from an imaging element. [Background technology]

[0002] Imaging devices that perform autofocus control using a phase difference signal obtained on the image plane of an imaging element are known. An imaging element capable of outputting such a phase difference signal has two photoelectric conversion units, each of which has a pupil divided for one microlens. If the pixel signals output from the two photoelectric conversion units are used as separate phase difference signals, they can be used to calculate the amount of blur in autofocus (AF). If the pixel signals output from the two photoelectric conversion units are added to generate an image signal, the image signals of effective pixels can be collected to generate a frame image representing the subject (see, for example, Patent Document 1). Recent imaging devices employ such imaging elements to perform high-precision AF even during video capture, enabling them to maintain focus even on moving subjects. Furthermore, the total number of pixels in an imaging element has gradually increased, resulting in improved focusing accuracy. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-134154 Summary of the Invention [Problem to be solved by the invention]

[0004] High frame rate (slow motion) mode, which captures images at a faster frame rate than normal and plays them back at the normal frame rate, allows users to enjoy smooth, slower-moving footage of moving subjects. High frame rate mode consumes a lot of power because pixel signals are read out at a faster frame rate than normal, and in some cases, the pixel signal readout process cannot keep up. When the pixel signal readout process cannot keep up, the AF process breaks down, making it impossible to maintain focus on the subject.

[0005] The present invention has been made to solve such problems, and provides an imaging device etc. that can achieve highly accurate subject tracking when imaging at a normal frame rate, and can continue AF processing while reducing power consumption when imaging at a frame rate faster than the normal frame rate. [Means for solving the problem]

[0006] An imaging device according to a first aspect of the present invention comprises an imaging element having a plurality of pixels arranged two-dimensionally, each pixel including a first photoelectric conversion unit that receives a light beam passing through a first partial region of an imaging optical system and a second photoelectric conversion unit that receives a light beam passing through a second partial region different from the first partial region; and a readout control unit that, when a first mode is selected, performs a first readout control in which the charges of the first photoelectric conversion unit and the second photoelectric conversion unit are separately AD converted to generate a pixel signal, and, when a second mode in which a frame rate faster than the frame rate set in the first mode is selected, performs a second readout control in which, at discretely set first pixels among the pixels, the charges of the first photoelectric conversion unit and the second photoelectric conversion unit are separately AD converted to generate a first pixel signal, and, at a second pixel among the pixels that is not the first pixel, the charges of the first photoelectric conversion unit and the second photoelectric conversion unit are added together and then AD converted to generate a second pixel signal.

[0007] In addition, a readout control method in a second aspect of the present invention has a computer execute the following steps: reading out pixel signals from an imaging element in which multiple pixels are two-dimensionally arranged, each pixel including a first photoelectric conversion unit that receives a light beam passing through a first partial region of an imaging optical system and a second photoelectric conversion unit that receives a light beam passing through a second partial region different from the first partial region; a receiving step of receiving a selection from a first mode and a second mode in which a frame rate faster than the frame rate set in the first mode is set; and a readout control step of, when the first mode is selected, performing a first readout control to separately AD-convert the charges of the first photoelectric conversion unit and the second photoelectric conversion unit to generate pixel signals, and when the second mode is selected, performing a second readout control to separately AD-convert the charges of the first photoelectric conversion unit and the second photoelectric conversion unit in first pixels that are discretely set among the pixels to generate first pixel signals, and to add the charges of the first photoelectric conversion unit and the second photoelectric conversion unit together and then AD-convert them in second pixels that are not the first pixels among the pixels to generate second pixel signals. [Effects of the Invention]

[0008] The present invention makes it possible to provide an imaging device or the like that can achieve highly accurate subject tracking when imaging at a normal frame rate, and can continue AF processing while reducing power consumption when imaging at a frame rate faster than the normal frame rate. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing the appearance of an imaging device according to an embodiment of the present invention. [Figure 2] FIG. 1 is a diagram illustrating a main hardware configuration of an imaging apparatus. [Figure 3] FIG. 2 is a diagram illustrating a pixel arrangement of an imaging element. [Figure 4] FIG. 2 is a diagram illustrating a configuration of a pixel. [Figure 5] 10A and 10B are diagrams illustrating pixel signal readout control by a readout control unit. [Figure 6] FIG. 2 is a diagram illustrating the setting of a first pixel and a second pixel. [Figure 7] FIG. 10 is a diagram illustrating a window width for generating a phase waveform. [Figure 8] FIG. 10 is a flowchart showing a processing procedure of a system control unit. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described below through embodiments of the invention, but the invention according to the claims is not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential as means for solving the problems. In each drawing, when multiple structures having the same or similar configurations exist, some may be given the same reference numerals and others may not be given the same reference numerals to avoid complication.

[0011] FIG. 1 is a diagram showing the appearance of an imaging device 100 according to this embodiment. In particular, FIG. 1(A) is a diagram mainly showing the first surface side of the imaging device 100, and FIG. 1(B) is a diagram mainly showing the second surface side opposite the first surface side. The imaging device 100 according to this embodiment is a so-called smartphone, in other words, a smartphone that also functions as an imaging device. In the following, we will explain the imaging function related to the present invention among the functions of a smartphone, and will omit explanation of other smartphone functions, such as the use of image data generated by imaging. Note that in this embodiment, the imaging device 100 will be described using a smartphone as an example, but it may of course also be an imaging device as a standalone camera, or a device incorporated into a tablet terminal or the like and equipped with an imaging function.

[0012] The imaging device 100 includes a first camera unit 110 and a second camera unit 120 arranged facing the same direction on the first surface side. The first camera unit 110 is a camera unit for generating wide-angle images. The second camera unit 120 is a camera unit for generating telephoto images. A user designates the first camera unit to capture an image when a wide-angle image is desired, and designates the second camera unit to capture an image when a telephoto image is desired. While the first camera unit 110 and the second camera unit 120 are shown arranged parallel to the long side of the imaging device 100 in the figure, the arrangement of the two camera units is not limited thereto, and they may be arranged, for example, along a straight line obliquely intersecting the long side. Furthermore, the arrangement of the first camera unit 110 and the second camera unit 120 may be reversed from the positions shown in the figure.

[0013] Imaging device 100 is provided with display 130 on the second surface side. Display 130 is a display device that employs, for example, an organic EL (Electro Luminescence) panel, and displays a real-time image of the subject before imaging (live view display), a real-time image during video imaging (rec view display), and an image after imaging. Note that a camera unit for taking selfies, independent of first camera unit 110 and second camera unit 120, may be provided on the second surface side.

[0014] A touch panel 162 is provided superimposed on the display 130. The user can instruct the imaging device 100 to capture a still image by tapping the shutter button displayed on the display 130, or to start or stop recording a video by tapping the video capture button. The user can also tap any point on the subject image displayed by live view or rec view to designate a certain area including that point as the focus area. In addition, the user can switch between the first camera unit 110 and the second camera unit 120 or select a displayed menu item by performing a contact operation such as tapping.

[0015] 2 is a diagram showing the main hardware configuration of the imaging device 100. In addition to the above-mentioned first camera unit 110, second camera unit 120, and display 130, the imaging device 100 is composed of a system control unit 150 that controls these units, and peripheral elements that work in cooperation with the system control unit 150.

[0016] As described above, the first camera unit 110 is a camera unit for generating a wide-angle image, and mainly includes a first optical system 111, a first drive mechanism 112, a first image sensor 113, and a first analog front end (AFE) 114. The first optical system 111 is an optical system for forming an image of an incident subject light beam on the imaging surface of the first image sensor 113. Although shown as a single lens in the figure, it is generally composed of multiple lenses, at least some of which are focus lenses that can advance and retreat along the optical axis direction. The first drive mechanism 112 is a drive mechanism for moving the focus lens of the first optical system 111 along the optical axis direction, and includes an actuator that operates according to instructions from the system control unit 150.

[0017] The first imaging element 113 is, for example, a CMOS image sensor. The first imaging element 113 will be described in detail later. The first imaging element 113 passes an output signal to the first AFE 114 under the control of the system control unit 150 and the first AFE 114. The first AFE 114 not only performs AD conversion control, which will be described later, but also adjusts the read timing of the output signal and adjusts the level according to a specified gain. The pixel signal adjusted by the first AFE 114 is passed to the work memory 151.

[0018] As described above, the second camera unit 120 is a camera unit for generating a telephoto image, and mainly includes a second optical system 121, a second drive mechanism 122, a second image sensor 123, and a second analog front end (AFE) 124. The second optical system 121 is an optical system for forming an image of an incident subject light beam on the imaging surface of the second image sensor 123. Although shown as a single lens in the figure, the second optical system 121, like the first optical system 111, is generally composed of multiple lenses, at least some of which are focus lenses that can advance and retreat along the optical axis direction. The second drive mechanism 122 is a drive mechanism for moving the focus lens of the second optical system 121 along the optical axis direction, and includes an actuator that operates according to instructions from the system control unit 150.

[0019] The second imaging element 123 is, for example, a CMOS image sensor. The second imaging element 123 will be described in detail later together with the first imaging element 113. The second imaging element 123 passes an output signal to the second AFE 114 under the control of the system control unit 150 and the second AFE 124. In addition to performing AD conversion control, which will be described later, the second AFE 124 adjusts the read timing of the output signal and adjusts the level according to a specified gain. The pixel signal adjusted by the second AFE 124 is passed to the work memory 151. Note that, in this embodiment, both the first optical system 111 and the second optical system 121 are assumed to be single-focus optical systems with fixed focal lengths, but at least one of them may be a variable-focus optical system (zoom lens) with a variable focal length.

[0020] The system control unit 150 is a processor (CPU: Central Processing Unit) that directly or indirectly controls each element that constitutes the imaging device 100. The system control unit 150 plays the role of various function control units depending on the control method being executed. For example, when executing autofocus control of the first camera unit 110 and the second camera unit 120, the system control unit 150 functions as a detection unit that performs phase difference detection on the subject image, and when displaying the captured image on the display 130, the system control unit 150 functions as a display control unit. In particular, in this embodiment, the system control unit 150 functions as a readout control unit that reads out output signals from the first imaging element 113 and the second imaging element 123 and generates pixel signals. Specific control by the readout control unit will be described later.

[0021] The imaging device 100 mainly includes a work memory 151, an image processing unit 152, an operation unit 160, a recording unit 170, and a communication interface 180 as peripheral elements that cooperate with the system control unit 150. The work memory 151 is a volatile high-speed memory, such as a static random access memory (SRAM). The work memory 151 receives sequentially converted pixel signals from the first AFE 114 and the second AFE 124, collectively stores the converted pixel signals as frame data for one frame. The work memory 151 also extracts specific pixel signals as phase difference signals, and generates and stores phase waveform data used to calculate the amount of blurring in AF. The work memory 151 passes the frame data to the image processing unit 153 and passes the phase waveform data to the system control unit 150. The work memory 151 is also used as a temporary storage area as appropriate during the image processing stage performed by the image processing unit 153 and the focusing stage performed by the system control unit 150.

[0022] The image processing unit 153 is configured, for example, by an ASIC (Application Specific Integrated Circuit) dedicated to image processing, and performs various image processing such as interpolation on the received frame data to generate image data in a predetermined format. If the generated image data is for recording, it is recorded in the recording unit 170, and if it is for display, it is displayed on the display 130.

[0023] The operation unit 160 is an input device including a touch panel 162, and is a member that the user operates to give instructions to the imaging device 100. If the imaging device 100 accepts audio input, the operation unit 160 may also include a microphone. The recording unit 170 is a non-volatile memory, and is configured, for example, by an SSD (Solid State Drive). In addition to recording image data generated by imaging, the recording unit 170 also holds constants, variables, setting values, control programs, etc. required for operation of the imaging device 100. The communication interface 180 may include a communication unit for a 5G line or a wireless LAN. The communication interface 180 is used when transferring the generated image data to an external device, etc.

[0024] Next, the structure of the imaging element and readout control of pixel signals will be described. In this embodiment, the first imaging element 113 and the second imaging element 123 employ imaging elements having the same structure, and the first AFE 114 and the second AFE 124 execute the same readout control for these imaging elements. Therefore, assuming that the first camera unit 110 captures moving images, the structure of the first imaging element 113 (hereinafter simply referred to as "imaging element 113") and readout control by the system control unit 150 (readout control unit) via the first AFE 114 (hereinafter simply referred to as "AFE 114") will be described.

[0025] 3 is a diagram illustrating the pixel array of the image sensor 113. In the image sensor 113, each pixel 200 includes a first photoelectric conversion unit 201 and a second photoelectric conversion unit 202, and a plurality of such pixels 200 are two-dimensionally arranged to form a pixel plane. The first photoelectric conversion unit 201 and the second photoelectric conversion unit 202 each form a substantially rectangular shape obtained by substantially dividing a square pixel region into two equal parts. With respect to the center of the pixel 200, the first photoelectric conversion unit 201 is offset in a first direction (to the left in the figure), and the second photoelectric conversion unit 202 is offset in a second direction opposite to the first direction (to the right in the figure). In one possible embodiment, each of the pixels 200 may include two or more photoelectric conversion units, for example, four, and it should be understood that the four photoelectric conversion units may be arranged in a 2x2 array, for example.

[0026] FIG. 4 is a diagram illustrating the configuration of the pixel 200, and is a diagram that schematically shows a cross section of the first optical system 111 (hereinafter simply referred to as “optical system 111”), a cross section of the pixel 200, and part of the circuit of the AFE 114.

[0027] The first photoelectric conversion unit 201 receives a light beam that passes through a first partial area PA1 of the optical system 111, which is an imaging optical system. The second photoelectric conversion unit 202 receives a light beam that passes through a second partial area PA2, which is different from the first partial area PA1 of the optical system 111. The first partial area PA1 and the second partial area PA2 may have an overlapping area. Both light beams pass through a microlens 211 and a color filter 212 arranged above the pixel and reach the respective photoelectric conversion unit.

[0028] The charge accumulated in the first photoelectric conversion unit 201 is converted into a digital signal by the AD converter 230 when the first switch 221 is closed, and is output as a pixel signal. The charge accumulated in the second photoelectric conversion unit 202 is converted into a digital signal by the AD converter 230 when the second switch 222 is closed, and is output as a pixel signal.

[0029] 5 is a diagram illustrating the readout control of pixel signals by the readout control unit. The readout control unit can generate pixel signals by executing either individual readout control or batch readout control for the pixels 200 in a charge accumulation state.

[0030] FIG. 5A is a diagram illustrating individual readout control. In individual readout control, first, as shown in the upper diagram of FIG. 5A, the readout control unit closes the first switch 221 and leaves the second switch 222 open, thereby causing the AD converter 230 to perform AD conversion on only the charge accumulated in the first photoelectric conversion unit 201 and output a pixel signal A. At this time, there is no change in the charge accumulated in the second photoelectric conversion unit 202. Next, as shown in the lower diagram of FIG. 5A, the readout control unit closes the second switch 222 and opens the first switch 221, thereby causing the AD converter 230 to perform AD conversion on only the charge accumulated in the second photoelectric conversion unit 202 and output a pixel signal B. In this way, by repeating AD conversion twice, a pixel signal A corresponding to the charge of the first photoelectric conversion unit 201 and a pixel signal B corresponding to the charge of the second photoelectric conversion unit 202 can be sequentially output. Since pixel signal A and pixel signal B are both signals generated from the same pixel, they are collectively referred to as a first pixel signal here. Note that the order in which pixel signal A and pixel signal B are generated may be reversed.

[0031] 5(B) is a diagram illustrating batch readout control. In batch readout control, the readout control unit closes both the first switch 221 and the second switch 222, adds the charges accumulated in the first photoelectric conversion unit 201 and the second photoelectric conversion unit 202, performs AD conversion on the added charges by the AD converter 230, and outputs a second pixel signal. In this way, a second pixel signal corresponding to the added charge of the first photoelectric conversion unit 201 and the second photoelectric conversion unit 202 can be output by a single AD conversion.

[0032] When a normal imaging mode with a normal frame rate (e.g., 30 fps or 60 fps) is selected, the readout control unit executes first readout control, which applies individual readout control to all pixels. In this case, the pixel value of the pixel in the frame data is determined by adding the pixel value of pixel signal A, which is the first pixel signal, and the pixel value of pixel signal B. Furthermore, by separately collecting pixel signals A and B of a pixel group corresponding to a specific subject image designated by the user or selected by an automatic algorithm, phase waveform data for the specific subject image can be generated. In other words, if first pixel signals are generated from all pixels, dense phase waveform data can be generated for any subject, and a highly accurate focus state can be maintained even for a moving subject during the imaging period.

[0033] On the other hand, if the first readout control is performed when capturing images at a frame rate faster than the normal frame rate (for example, 120 fps or 240 fps), two AD conversions are required for each pixel, resulting in a significant increase in power consumption. This increase in power consumption not only shortens the usage time of the imaging device, but can also cause the operation of the imaging device to become unstable due to the heat generated. Furthermore, the processing time required for the two AD conversions and the processing time required to process the enormous amount of generated first pixel signals may not fit within the frame rate cycle. In other words, the readout process and data processing may not be able to keep up with the high frame rate. In this situation, not only will it be impossible to maintain focus on the subject, but it may also be impossible to generate frame images.

[0034] Therefore, in this embodiment, when an imaging mode in which a high frame rate is set is selected, a second readout control that combines individual readout control and batch readout control is executed. An example of an imaging mode in which a high frame rate is set is a high frame mode (slow motion mode), in which images of a subject moving smoothly but at a slower rate than in reality can be enjoyed by playing back at a normal frame rate.

[0035] When the second readout control is performed, all effective pixels of the image sensor 111 are set in advance to be divided into first pixels to which individual readout control is applied and second pixels to which collective readout control is applied. Fig. 6 is a diagram illustrating the setting of the first and second pixels when the second readout control is performed. In the figure, the pixels surrounded by a thick frame are set as first pixels 200a, and the other pixels are set as second pixels 200b.

[0036] In the illustrated example, the first pixels 200a are periodically arranged at a ratio of one for every five pixels vertically and five pixels horizontally. By discretely arranging the first pixels 200a surrounded by the second pixels 200b in this manner, the number of first pixels 200a for which individual readout control is performed can be significantly reduced. By significantly reducing the number of first pixels 200a, overall power consumption can be reduced. Furthermore, since the amount of pixel signals generated can be reduced, the time required for calculation processing can be shortened, and AF processing and frame image generation can be continued appropriately even at a high frame rate.

[0037] However, because the phase waveform data for AF processing can only be obtained from the discretely arranged first pixels 200a, it is necessary to consider the balance with the reduction in focusing accuracy. In other words, the ratio of the first pixels 200a to the second pixels 200b is determined by considering the balance between the advantages of power saving and high-speed processing and the disadvantage of reduced focusing accuracy. For example, if the user can select multiple frame rates, adjustments can be made such as decreasing the ratio of the first pixels 200a to the second pixels 200b for faster frame rates. The discretely arranged first pixels 200a for AF processing may be arranged in a variety of ways. For example, they may be arranged evenly at a fixed ratio, i.e., the first pixels 200a may be distributed across all pixels at a fixed ratio. This method can maintain uniform overall focusing performance, or more first pixels 200a may be arranged in the center of the image and fewer first pixels 200a may be arranged on the edges. It should be understood that such a center-prioritized arrangement method is used for portrait mode or a mode that emphasizes a specific part, providing better focusing performance in the center of the image.

[0038] Furthermore, in order to improve the focusing accuracy even with the limited number of first pixels 200a, the window width for generating the phase waveform may be adjusted. Fig. 7 is a diagram illustrating the window width for generating the phase waveform.

[0039] 7A shows the first window width that is set when performing the first readout control that applies individual readout control to all pixels 200. The first window width is set to W1 pixels, and when performing the first readout control, the detection unit generates a phase waveform using pixel signals A and B generated from these pixels 200, and performs phase difference detection for the subject image to achieve focusing.

[0040] 7B shows the second window width set when performing second readout control, which combines individual readout control and batch readout control. The second window width is set to W2 pixels, which is greater than W1 pixels. When performing second readout control, the detection unit generates a phase waveform using pixel signal A and pixel signal B generated from the first pixel 200a that is the target of individual readout control among the pixels 200 included in this second window width, and performs phase difference detection for the subject image.

[0041] That is, when performing the second readout control, if the same first window width as that when performing the first readout control is set, the phase waveform that can be generated will be short. However, by setting a second window width larger than the first window width and lengthening the length of the phase waveform to be generated, the decrease in accuracy of phase difference detection is compensated for. However, if the window width is increased, the possibility of capturing multiple subjects across each other increases, making perspective conflict more likely to occur. Therefore, it is advisable to appropriately set the window width according to the ratio of the first pixel 200a to the second pixel 200b.

[0042] Next, a description will be given of the processing procedure of the system control unit 150 in a series of moving image shooting processes. Fig. 8 is a flowchart showing the processing procedure of the system control unit 150.

[0043] In step S101, the system control unit 150 receives from the user a selection between a first mode in which a normal frame rate is set and a second mode in which a frame rate faster than the normal frame rate is set. The system control unit 150 switches to the selected imaging mode and waits for an instruction to start imaging from the user in step S102. If the instruction to start imaging is received, the system control unit 150 proceeds to step S103, where it checks the current imaging mode. If it is the first mode (normal frame rate), it proceeds to step S104, and if it is the second mode (higher frame rate), it proceeds to step S108.

[0044] When the process proceeds from step S103 to step S104, the system control unit 150, functioning as a readout control unit, executes first readout control. In the following step S105, the system control unit 150, functioning as a detection unit, generates a phase waveform from a first window width set for a pixel group corresponding to a specific subject image, performs phase difference detection, and executes AF processing. In the following step S106, the system control unit 150 generates one frame of frame data in accordance with the set normal frame rate. In step S107, the system control unit 150 checks whether an instruction to stop image capture has been received from the user. If an instruction to stop image capture has not been received, the process returns to step S104 to continue video capture; if an instruction to stop image capture has been received, the system control unit 150 performs the set formatting process on the frame data accumulated up to that point to generate a video file, and the process ends.

[0045] When the process proceeds from step S103 to step S108, the system control unit 150, functioning as a readout control unit, executes second readout control. In the following step S109, the system control unit 150, functioning as a detection unit, generates a phase waveform from the second window width set for the pixel group corresponding to the specific subject image, performs phase difference detection, and executes AF processing. In the following step S110, the system control unit 150 generates one frame's worth of frame data in accordance with the set high-speed frame rate. In step S111, the system control unit 150 checks whether an instruction to stop image capture has been received from the user. If an instruction to stop image capture has not been received, the process returns to step S108 to continue video capture; if an instruction to stop image capture has been received, the system control unit 150 performs the set formatting process on the frame data accumulated up to that point to generate a video file, and the series of processes ends.

[0046] In the embodiment described above, it is assumed that a moving image is captured, but similar focus control can be performed even when a still image is captured. That is, when a still image is captured each time the shutter button is tapped or when an imaging mode for capturing continuous images at a low speed is selected, a first readout control that applies individual readout control to all of the pixels 200 can be applied, and when an imaging mode for capturing continuous images at a high speed is selected, a second readout control that combines individual readout control and batch readout control can be applied. In one possible embodiment, two or more imaging modes may be provided based on different imaging frame rates or continuous shooting speeds. Each mode corresponds to different focusing accuracy. For example, the higher the frame rate / faster the continuous shooting speed, the fewer pixels are used for focusing, providing flexibility in balancing power consumption and performance. [Explanation of symbols]

[0047] 100...imaging device, 110...first camera unit, 111...first optical system (optical system), 112...first drive mechanism (drive mechanism), 113...first image sensor (image sensor), 114...first analog front end (AFE), 120...second camera unit, 121...second optical system, 122...second drive mechanism, 123...second image sensor, 124...second analog front end, 130...display, 150...system System control unit, 151...work memory, 152...image processing unit, 160...operation unit, 162...touch panel, 170...recording unit, 180...communication interface, 200...pixel, 200a...first pixel, 200b...second pixel, 201...first photoelectric conversion unit, 202...second photoelectric conversion unit, 210...microlens, 212...color filter, 221...first switch, 222...second switch, 230...AD converter

Claims

1. An imaging device, an image sensor in which a plurality of pixels are two-dimensionally arranged, each pixel including at least a first photoelectric conversion unit that receives a light beam passing through a first partial region of an imaging optical system and a second photoelectric conversion unit that receives a light beam passing through a second partial region different from the first partial region; a readout control unit that performs first readout control, when a first mode is selected, to separately AD convert the charges of the first photoelectric conversion unit and the second photoelectric conversion unit to generate pixel signals, and when a second mode, in which a frame rate faster than a frame rate set in the first mode is selected, performs second readout control, when a first mode is selected and a frame rate faster than a frame rate set in the first mode is selected, to separately AD convert the charges of the first photoelectric conversion unit and the second photoelectric conversion unit to generate first pixel signals, and when a second pixel, which is not the first pixel, among the pixels, performs second readout control, when a second pixel, which is not the first pixel among the pixels, Equipped with the imaging device includes a detection unit, When the readout control unit performs the second readout control, the detection unit increases a window width for generating a phase waveform compared to when the readout control unit performs the first readout control.

2. The imaging device described in Claim 1, wherein the detection unit performs phase difference detection autofocus using pixel signals obtained by separately AD-converting the charges of the first photoelectric conversion unit and the second photoelectric conversion unit.

3. A read control method, comprising: reading out pixel signals from an image sensor in which a plurality of pixels are two-dimensionally arranged, each pixel including a first photoelectric conversion unit that receives a light beam passing through a first partial region of an imaging optical system and a second photoelectric conversion unit that receives a light beam passing through a second partial region different from the first partial region; determining one mode from a first mode and a second mode in which a frame rate higher than that set in the first mode is set; a step of performing a first readout control in the first mode to separately AD convert the charges of the first photoelectric conversion unit and the second photoelectric conversion unit to generate a pixel signal, and performing a second readout control in the second mode to separately AD convert the charges of the first photoelectric conversion unit and the second photoelectric conversion unit to generate a first pixel signal in first pixels that are discretely set among the pixels, and to add up the charges of the first photoelectric conversion unit and the second photoelectric conversion unit and then AD convert the sum to generate a second pixel signal in second pixels that are not the first pixels among the pixels, A readout control method, wherein, when the second readout control is performed, a window width for generating a phase waveform is made larger than when the first readout control is performed.

4. performing phase difference detection autofocus using pixel signals obtained by separately AD-converting the charges of the first photoelectric conversion unit and the second photoelectric conversion unit; The read control method according to claim 3 .

Images