Pixel circuit, image sensor, camera module, device and automatic focusing method

Abstract

The present application discloses a pixel circuit, an image sensor, a camera module, a device and an autofocus method, which belong to the field of camera technology. The pixel circuit includes a plurality of rows and columns of pixel units and a plurality of signal readout units; the input ends of the plurality of signal readout units are electrically connected one by one with the plurality of rows of pixel units; the output ends of the plurality of signal readout units are electrically connected one by one with a plurality of analog-to-digital converters; each pixel unit includes a first phase subunit, a second phase subunit and n rows and n columns of pixel subunits, and the pixel subunits included in the same pixel unit have the same color; the first end of the first phase subunit is electrically connected to the positive electrode of the photosensitive element included in the pixel subunits in the 1st to th rows; the first end of the second phase subunit is electrically connected to the positive electrode of the photosensitive element included in the pixel subunits in the th to nth rows; the second end of the first phase subunit and the second end of the second phase subunit are electrically connected to the analog-to-digital converter.

Description

Technical Field

[0001] The present application belongs to the field of camera technology, and specifically relates to a pixel circuit, an image sensor, a camera module, a device and an autofocus method. Background Art

[0002] The industry of electronic devices such as mobile phones and cameras is highly competitive, and there is an increasing demand for clearer pictures. This poses a huge challenge to the autofocus capability of electronic device cameras.

[0003] In the related art, in order to improve the autofocus capability of electronic devices, electronic devices usually use density-type phase detection auto focus (PDAF) or full-pixel PDAF for autofocus. However, the density-type PDAF has poor focusing capability, while the full-pixel PDAF has better focusing capability, but it will lead to higher power consumption of electronic devices. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a pixel circuit, an image sensor, a camera module, a device and an autofocus method, which can improve the focusing ability of an electronic device while affecting the power consumption of the electronic device.

[0005] In a first aspect, an embodiment of the present application provides a pixel circuit, comprising: a plurality of rows and columns of pixel units and a plurality of signal readout units;

[0006] The input ends of the plurality of signal readout units are electrically connected one by one to the plurality of rows of pixel units;

[0007] The plurality of signal readout units are electrically connected one by one to the plurality of analog-to-digital converters; the signal readout units are used to read out the voltage signal corresponding to each row of pixel units to the analog-to-digital converter;

[0008] Each pixel unit includes a first phase subunit, a second phase subunit and pixel subunits in n rows and n columns, wherein n is a positive integer greater than or equal to 2, and the pixel subunits included in the same pixel unit have the same color;

[0009] The first end of the first phase subunit is connected to the first to the second The positive electrode of the photosensitive element included in the row pixel subunit is electrically connected;

[0010] The first terminal of the second phase subunit is connected to the The positive electrodes of the photosensitive elements included in the pixel sub-units in the nth row are electrically connected;

[0011] The second end of the first phase subunit and the second end of the second phase subunit are electrically connected to the analog-to-digital converter.

[0012] In a second aspect, an embodiment of the present application provides an image sensor, including:

[0013] The pixel circuit provided by the embodiment of the present application.

[0014] In a third aspect, an embodiment of the present application provides a camera module, including:

[0015] An image sensor provided in an embodiment of the present application.

[0016] In a fourth aspect, an embodiment of the present application provides an electronic device, including:

[0017] The camera module provided in the embodiment of the present application.

[0018] A fifth method, an embodiment of the present application provides an auto-focus method, which is applied to the electronic device provided in an embodiment of the present application, and the method includes:

[0019] Obtaining a first phase corresponding to a first-side pixel sub-unit in the pixel sub-units of n rows and n columns;

[0020] Acquire a second phase corresponding to a second side pixel sub-unit in the pixel sub-units of n rows and n columns;

[0021] Determine a phase difference between the first phase and the second phase according to the first phase and the second phase;

[0022] Based on the phase difference, the camera of the electronic device is controlled to perform automatic focusing.

[0023] In an embodiment of the present application, a pixel circuit includes a plurality of rows and columns of pixel units and a plurality of signal readout units; input ends of the plurality of signal readout units are electrically connected one by one to the plurality of rows of pixel units; output ends of the plurality of signal readout units are electrically connected one by one to the analog-to-digital converter; the signal readout unit is used to read out a voltage signal corresponding to each row of pixel units to the analog-to-digital converter; each pixel unit includes a first phase subunit, a second phase subunit, and n rows and n columns of pixel subunits, wherein n is a positive integer greater than or equal to 2, and the pixel subunits included in the same pixel unit have the same color; a first end of the first phase subunit is electrically connected to the pixels in the 1st to 2nd rows; a second phase subunit is electrically connected to the pixels in the 1st to 2nd rows; a second phase subunit is electrically connected to the pixels in the 2nd to 3rd rows; a first end of the first phase subunit is electrically connected to the pixels in the 2nd to 3rd rows; a second ... The positive electrode of the photosensitive element included in the row pixel subunit is electrically connected; the first end of the second phase subunit is electrically connected to the first The positive electrodes of the photosensitive elements included in the pixel subunits from the row to the nth row are electrically connected; the second end of the first phase subunit and the second end of the second phase subunit are electrically connected to the analog-to-digital converter. The phase difference is determined by the electrical signal of the positive electrode of the photosensitive element, and then automatic focusing is performed based on the phase difference, which can improve the focusing ability of the electronic device without affecting the power consumption of the electronic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1is a schematic diagram of the structure of a pixel circuit provided in an embodiment of the present application;

[0025] Figure 2 This is a schematic diagram of the first structure of a pixel unit provided in an embodiment of the present application;

[0026] Figure 3 is a schematic diagram of a second structure of a pixel unit provided in an embodiment of the present application;

[0027] Figure 4 is a third structural schematic diagram of a pixel unit provided in an embodiment of the present application;

[0028] Figure 5 is a fourth structural schematic diagram of a pixel unit provided in an embodiment of the present application;

[0029] Figure 6 is a fifth structural schematic diagram of a pixel unit provided in an embodiment of the present application;

[0030] Figure 7 is a sixth structural schematic diagram of a pixel unit provided in an embodiment of the present application;

[0031] Figure 8 is a schematic diagram of a specific structure of a pixel unit provided in an embodiment of the present application;

[0032] Fig. 9 is a flowchart of an automatic focusing method according to an embodiment of the present application;

[0033] Fig.10 It is a schematic diagram of the hardware structure of an electronic device implementing an embodiment of the present application. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0035] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0036] The pixel circuit, image sensor, camera module, device and autofocus method provided in the embodiments of the present application are described in detail below with reference to the accompanying drawings through specific embodiments and their application scenarios.

[0037] The pixel circuit provided by the embodiment of the present application includes multiple rows and columns of pixel units and multiple signal readout units; the input ends of the multiple signal readout units are electrically connected one by one to the multiple rows of pixel units; the output ends of the multiple signal readout units are electrically connected one by one to the multiple analog-to-digital converters; the signal readout unit is used to read out the voltage signal corresponding to each row of pixel units to the analog-to-digital converter.

[0038] In some possible implementations of the embodiments of the present application, the pixel units of multiple rows and columns in the embodiments of the present application are pixel units of at least two rows and at least two columns.

[0039] Exemplarily, the pixel circuit includes M rows and N columns of pixel units and M signal readout units, where M and N are positive integers greater than or equal to 2. The input end of the i-th signal readout unit is electrically connected to the i-th row of pixel units, and the output end of the i-th signal readout unit is electrically connected to the i-th analog-to-digital converter, where i is a positive integer less than or equal to M.

[0040] like Figure 1 As shown, Figure 1 is a schematic diagram of the structure of a pixel circuit provided in an embodiment of the present application. Figure 1 In the figure, the pixel circuit 100 includes a plurality of rows and columns of pixel units 11 and a plurality of signal readout units 12; the output ends of the signal readout units 12 electrically connected to each row of pixel units are electrically connected to an analog-to-digital converter 200; the analog-to-digital converter 13 converts the sampled voltage signals of each row of pixel units into digital signals, and then sends the digital signals to an image signal processor (ISP) to generate an image.

[0041] In some possible implementations of the embodiments of the present application, each pixel unit in the embodiments of the present application includes a first phase subunit, a second phase subunit, and n rows and n columns of pixel subunits, wherein n is a positive integer greater than or equal to 2, and the pixel subunits included in the same pixel unit have the same color; the first end of the first phase subunit is connected to the pixels in the 1st to 2nd rows; The positive electrode of the photosensitive element included in the row pixel subunit is electrically connected; the first end of the second phase subunit is electrically connected to the first The positive electrodes of the photosensitive elements included in the pixel subunits from row to the nth row are electrically connected; the second end of the first phase subunit and the second end of the second phase subunit are electrically connected to the analog-to-digital converter.

[0042] It can be understood that when n is 2, the pixel unit is a four-in-one pixel unit, when n is 3, the pixel unit is a nine-in-one pixel unit, and when n is 4, the pixel unit is a sixteen-in-one pixel unit.

[0043] The colors corresponding to the pixel sub-units included in the same pixel unit may be red, red-green, cyan, or blue.

[0044] like Figure 2 As shown, Figure 2 is a schematic diagram of the first structure of a pixel unit provided in an embodiment of the present application. Figure 2 In the embodiment, the pixel unit 11 comprises a first phase subunit 112, a second phase subunit 113 and n rows and n columns of pixel subunits 111. The first end of the first phase subunit 112 is connected to the pixels of the 1st to 2nd rows. The positive electrode of the photosensitive element PD included in the row pixel subunit is electrically connected; the first end of the second phase subunit 113 is electrically connected to the first The positive electrodes of the photosensitive elements PD included in the pixel sub-units from row to the nth row are electrically connected; the second end of the first phase sub-unit 112 and the second end of the second phase sub-unit 113 are electrically connected to the analog-to-digital converter 200 .

[0045] In some possible implementations of the embodiments of the present application, the pixel subunit includes a first switching tube, a photosensitive element, and a second switching tube; the negative electrode of the photosensitive element is electrically connected to the source of the first switching tube; the drain of the first switching tube is electrically connected to the signal readout unit corresponding to the pixel unit including the photosensitive element; the positive electrode of the photosensitive element is electrically connected to the drain of the second switching tube; and the source of the second switching tube is grounded.

[0046] like Figure 3 As shown, Figure 3 is a schematic diagram of a second structure of a pixel unit provided in an embodiment of the present application. Figure 3 In the figure, the pixel subunit 111 includes a first switch tube TG1, a photosensitive element PD and a second switch tube TG2; the cathode of the photosensitive element PD is electrically connected to the source of the first switch tube TG1; the drain of the first switch tube TG1 is electrically connected to the signal readout unit 12 corresponding to the pixel unit including the photosensitive element PD; the anode of the photosensitive element PD is electrically connected to the drain of the second switch tube TG2; the source of the second switch tube TG2 is grounded.

[0047] In some possible implementations of the embodiments of the present application, the first phase subunit includes: a third switch tube and a first capacitor; the second phase subunit includes: a fourth switch tube and a second capacitor; the drain of the third switch tube is connected to the first to the second capacitor. The positive electrode of the photosensitive element of the row pixel subunit is electrically connected; the source electrode of the third switch tube is electrically connected to the first plate of the first capacitor; the drain electrode of the fourth switch tube is electrically connected to the first The positive electrode of the photosensitive element of the nth row of pixel sub-units is electrically connected; the source electrode of the fourth switch tube is electrically connected to the first plate of the second capacitor; the second plate of the first capacitor and the second plate of the second capacitor are grounded.

[0048] like Figure 4 As shown, Figure 4 is a third structural schematic diagram of a pixel unit provided in an embodiment of the present application. Figure 4 In the embodiment, the first phase subunit 112 includes a third switch tube TG3 and a first capacitor C1, and the second phase subunit 113 includes a fourth switch tube TG4 and a second capacitor C2. The positive electrode of the photosensitive element PD of the row pixel subunit is electrically connected; the source electrode of the third switch tube TG3 is electrically connected to the first plate of the first capacitor C1; the drain electrode of the fourth switch tube TG4 is electrically connected to the first plate of the first capacitor C1; The positive electrode of the photosensitive element PD of the nth row of pixel sub-units is electrically connected; the source of the fourth switch tube TG4 is electrically connected to the first plate of the second capacitor C2; the second plate of the first capacitor C1 and the second plate of the second capacitor C2 are grounded.

[0049] In some possible implementations of the embodiments of the present application, the first phase subunit also includes: a fifth switching tube; the second phase subunit also includes a sixth switching tube; the drain of the fifth switching tube and the drain of the sixth switching tube are respectively connected to the power supply; the source of the fifth switching tube is electrically connected to the first plate of the first capacitor; the source of the sixth switching tube is electrically connected to the first plate of the second capacitor.

[0050] like Figure 5 As shown, Figure 5 is a fourth structural schematic diagram of a pixel unit provided in an embodiment of the present application. Figure 5 In the embodiment, the first phase subunit 112 includes a third switch tube TG3, a first capacitor C1 and a fifth switch tube TG5, and the second phase subunit 113 includes a fourth switch tube TG4, a second capacitor C2 and a sixth switch tube TG6. The drain of the third switch tube TG3 is connected to the first to the second phase subunits. The positive electrode of the photosensitive element PD of the row pixel subunit is electrically connected; the source electrode of TG3 is electrically connected to the first plate of the first capacitor C1; the drain electrode of the fourth switch tube TG4 is electrically connected to the first The positive electrode of the photosensitive element PD of the n-th row of pixel sub-units is electrically connected; the source of the fourth switch tube TG4 is electrically connected to the first plate of the second capacitor C2; the second plate of the first capacitor C1 and the second plate of the second capacitor C2 are grounded; the drain of the fifth switch tube TG5 and the drain of the sixth switch tube TG6 are respectively connected to the power supply; the source of the fifth switch tube TG5 is electrically connected to the first plate of the first capacitor C1; the source of the sixth switch tube TG6 is electrically connected to the first plate of the second capacitor C2.

[0051] When the fifth switch tube TG5 is turned on, the first capacitor C1 is cleared; when the sixth switch tube TG6 is turned on, the second capacitor C2 is cleared.

[0052] In some possible implementations of the embodiments of the present application, the first phase sub-unit also includes: a seventh switch tube; the second phase sub-unit also includes an eighth switch tube; the drain of the seventh switch tube and the drain of the eighth switch tube are respectively connected to the power supply; the source of the seventh switch tube and the source of the eighth switch tube are electrically connected to the analog-to-digital converter; the gate of the seventh switch tube is electrically connected to the first plate of the first capacitor; the gate of the eighth switch tube is electrically connected to the first plate of the second capacitor.

[0053] like Figure 6 As shown, Figure 6 is a fifth structural diagram of a pixel unit provided in an embodiment of the present application. Figure 6 In the embodiment, the first phase subunit 112 includes a third switch tube TG3, a first capacitor C1 and a seventh switch tube TG7, and the second phase subunit 113 includes a fourth switch tube TG4, a second capacitor C2 and an eighth switch tube TG8. The drain of the third switch tube TG3 is connected to the first to the second phase subunits. The positive electrode of the photosensitive element PD of the row pixel subunit is electrically connected; the source electrode of TG3 is electrically connected to the first plate of the first capacitor C1; the drain electrode of the fourth switch tube TG4 is electrically connected to the first The positive electrode of the photosensitive element PD of the pixel sub-unit in the nth row is electrically connected; the source of the fourth switch tube TG4 is electrically connected to the first plate of the second capacitor C2; the second plate of the first capacitor C1 and the second plate of the second capacitor C2 are grounded; the drain of the seventh switch tube TG7 and the drain of the eighth switch tube TG8 are respectively connected to the power supply; the source of the seventh switch tube TG7 and the source of the eighth switch tube TG8 are respectively electrically connected to the analog-to-digital converter 200; the gate of the seventh switch tube TG7 is electrically connected to the first plate of the first capacitor C1; the gate of the eighth switch tube TG8 is electrically connected to the first plate of the second capacitor C2.

[0054] The voltage signal of the first capacitor C1 is transmitted to the analog-to-digital converter for reading through the seventh switch tube TG7 ; the voltage signal of the second capacitor C2 is transmitted to the analog-to-digital converter for reading through the eighth switch tube TG8 .

[0055] In some possible implementations of the embodiments of the present application, the first capacitor and the second capacitor in the embodiments of the present application are variable capacitors.

[0056] In some possible implementations of the embodiments of the present application, the pixel unit also includes a ninth switch tube; the drain of the ninth switch tube is electrically connected to the drain of the third switch tube; and the source of the ninth switch tube is electrically connected to the drain of the fourth switch tube.

[0057] like Figure 7 As shown, Figure 7is a sixth structural diagram of a pixel unit provided in an embodiment of the present application. Figure 7 In the embodiment, the first phase subunit 112 includes a third switch tube TG3 and a first capacitor C1, and the second phase subunit 113 includes a fourth switch tube TG4 and a second capacitor C2. The positive electrode of the photosensitive element PD of the row pixel subunit is electrically connected; the source electrode of TG3 is electrically connected to the first plate of the first capacitor C1; the drain electrode of the fourth switch tube TG4 is electrically connected to the first The positive electrode of the photosensitive element PD of the pixel sub-unit of the nth row is electrically connected; the source of the fourth switch tube TG4 is electrically connected to the first plate of the second capacitor C2; the second plate of the first capacitor C1 and the second plate of the second capacitor C2 are grounded. The drain of the ninth switch tube TG9 is electrically connected to the drain of the third switch tube TG3; the source of the ninth switch tube TG9 is electrically connected to the drain of the fourth switch tube TG4.

[0058] Figure 8 It is a specific structural schematic diagram of a pixel unit provided in an embodiment of the present application.

[0059] exist Figure 8 In the embodiment, the pixel unit 11 includes a first phase subunit 112, a second phase subunit 113, a ninth switch tube TG9 and pixel subunits 111 of 2 rows and 2 columns. The pixel subunit 111 includes a first switch tube TG1, a second switch tube TG2 and a photosensitive element PD, the first phase subunit 112 includes a third switch tube TG3, a fifth switch tube TG5 and a first capacitor C1, and the second phase subunit 113 includes a fourth switch tube TG4, a sixth switch tube TG6 and a second capacitor C2. The first phase subunit 112 and the second phase subunit 113 share a signal amplifier TG10 and a row selector TG11; the signal readout unit 12 includes a reset transistor RST, a parasitic capacitor FD, a signal amplifier SF and a row selector SET.

[0060] In some possible implementations of the embodiments of the present application, the switch tube, signal amplifier, row selector and reset transistor in the embodiments of the present application can be a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET).

[0061] The negative electrode of the photosensitive element PD is electrically connected to the source of the first switch tube TG1; the drain of the first switch tube TG1 is electrically connected to the drain of the reset transistor RST, the first plate of the parasitic capacitor FD and the gate of the signal amplifier SF, respectively, the second plate of the parasitic capacitor FD is grounded, the source of the reset transistor RST and the source of the signal amplifier SF are connected to the power supply, and the drain of the signal amplifier SF is electrically connected to the source of the row selector SET; the drain of the row selector SET is electrically connected to the positive electrode of the power supply DC and the analog-to-digital converter 200, respectively; the positive electrode of the photosensitive element PD is electrically connected to the drain of the second switch tube TG2; the source of the second switch tube TG2 is grounded.

[0062] The drain of the third switch tube TG3 is electrically connected to the positive electrode of the photosensitive element PD of the pixel sub-unit in the first row; the source of the third switch tube TG3 is electrically connected to the first plate of the first capacitor C1; the drain of the fourth switch tube TG4 is electrically connected to the positive electrode of the photosensitive element PD of the pixel sub-unit in the second row; the source of the fourth switch tube TG4 is electrically connected to the first plate of the second capacitor C2; the second plate of the first capacitor C1 and the second plate of the second capacitor C2 are grounded; the drain of the fifth switch tube TG5 and the drain of the sixth switch tube TG6 are connected to the power supply; the source of the fifth switch tube TG5 is electrically connected to the first plate of the first capacitor C1; the source of the sixth switch tube TG6 is electrically connected to the first plate of the second capacitor C2. The drain of the ninth switch tube TG9 is electrically connected to the drain of the third switch tube TG3; the source of the ninth switch tube TG9 is electrically connected to the drain of the fourth switch tube TG4. The gate of the signal amplifier TG10 is electrically connected to the source of the third switch tube TG3 and the source of the fourth switch tube TG4, and the drain of the signal amplifier TG10 is connected to the power supply; the source of the signal amplifier TG10 is electrically connected to the source of the row selector TG11, and the drain of the row selector TG11 is electrically connected to the analog-to-digital converter.

[0063] When the pixel is exposed, the reset transistor RST, the fifth switch tube TG5, the sixth switch tube TG6 and each pixel sub-unit including the first switch tube TG1 are turned on to clear the first capacitor C1, the second capacitor C2 and the parasitic capacitor FD. The electron-hole pairs generated by light irradiation will separate due to the existence of the electric field of the photosensitive element PD, the electrons move to the N area, and the holes move to the P area. After the exposure is completed, the reset transistor RST is closed to reset the parasitic capacitor FD to a high level. After the reset is completed, the reset level of the parasitic capacitor FD is read out through the signal amplifier SF and the row selector SET, and the signal read at this time is stored as a voltage signal value A, and the first switch tube TG1 included in each pixel sub-unit is closed to completely transfer the charge from the photosensitive area to the parasitic capacitor FD for a second readout. The voltage signal of the parasitic capacitor FD is read out for the second time through the signal amplifier SF and the row selector SET, and the signal read at this time is stored as the voltage signal value B. The two stored voltage signal values ​​are subtracted, and the obtained voltage signal is the voltage value corresponding to the pure light signal. The voltage value is then analog amplified and sampled by the analog-to-digital converter to obtain the digital signal corresponding to the light signal, and then the image is obtained.

[0064] When it is necessary to output the upper phase and the lower phase, the second switch tube TG2 at the positive end of the photosensitive element of the first row is disconnected, the ninth switch tube TG9 is disconnected, and the third switch tube TG3 and the fifth switch tube TG5 are closed, then all the holes of the photosensitive elements of the first row will be transmitted to the first capacitor C1. At this time, the capacitance of the first capacitor C1 needs to be adjusted to 1 / 2 times the capacitance of the parasitic capacitor FD; after the capacitance of the first capacitor C1 is adjusted to 1 / 2 times the capacitance of the parasitic capacitor FD, the total voltage on the first capacitor C1 is consistent with the image digital signal of the parasitic capacitor FD, and then transmitted to the analog-to-digital converter 200 for reading through the signal amplifier TG10 and the row selector TG11, and the obtained digital signal is the upper phase Information; disconnect the second switch tube TG2 at the positive end of the photosensitive element of the second row, disconnect the ninth switch tube TG9 and the fifth switch tube TG5, close the fourth switch tube TG4 and the sixth switch tube TG6, then all the holes of the photosensitive elements of the second row will be transmitted to the second capacitor C2, and at this time, the capacitance of the second capacitor C2 needs to be adjusted to 1 / 2 times the capacitance of the parasitic capacitor FD; after the capacitance of the second capacitor C2 is adjusted to 1 / 2 times the capacitance of the parasitic capacitor FD, the total voltage on the second capacitor C2 is consistent with the image digital signal magnitude of the parasitic capacitor FD, and then transmitted to the analog-to-digital converter 200 for reading through the signal amplifier TG10 and the row selector TG11, and the obtained digital signal is the lower phase information.

[0065] When the left phase and the right phase need to be output, the second switch tube TG2 at the positive end of the photosensitive element of the first column is disconnected, and the ninth switch tube TG9, the third switch tube TG3 and the fifth switch tube TG5 are closed, then the holes of the photosensitive element of the first column will be all transmitted to the first capacitor C1, and at this time, the capacitance of the first capacitor C1 needs to be adjusted to 1 / 2 times the capacitance of the parasitic capacitor FD; after the capacitance of the first capacitor C1 is adjusted to 1 / 2 times the capacitance of the parasitic capacitor FD, the total voltage on the first capacitor C1 is consistent with the image digital signal of the parasitic capacitor FD, and then transmitted to the analog-to-digital converter 200 for reading through the signal amplifier TG10 and the row selector TG11, and the obtained digital signal is the left phase information;

[0066] Close the second switch tube TG2 at the positive end of the photosensitive element in the first column, disconnect the second switch tube TG2 at the positive end of the photosensitive element in the second column, close the ninth switch tube TG9, the fourth switch tube TG4 and the sixth switch tube TG6, and disconnect the third switch tube TG3 and the fifth switch tube TG5, then all the holes of the photosensitive elements in the second column will be transmitted to the second capacitor C2. At this time, the capacitance of the second capacitor C2 needs to be adjusted to 1 / 2 times the capacitance of the parasitic capacitor FD; after the capacitance of the second capacitor C2 is adjusted to 1 / 2 times the capacitance of the parasitic capacitor FD, the total voltage on the second capacitor C2 is consistent with the magnitude of the image digital signal of the parasitic capacitor FD, and then transmitted to the analog-to-digital converter 200 for reading through the signal amplifier TG10 and the row selector TG11, and the obtained digital signal is the right phase information.

[0067] In some possible implementations of the embodiments of the present application, after obtaining the upper phase information and the lower phase information, the phase difference between the upper phase and the lower phase can be determined; after obtaining the left phase information and the right phase information, the phase difference between the left phase and the right phase can be determined.

[0068] In an embodiment of the present application, the phase difference is determined by the electrical signal of the positive electrode of the photosensitive element, and phase detection autofocus is performed based on the phase difference, which can improve the focusing capability of the electronic device without affecting the power consumption of the electronic device.

[0069] In some possible implementations of the embodiments of the present application, when zooming, the focal length of the lens changes, thereby changing the size of the preview image. At this time, a first pixel unit corresponding to the preview image is determined from the pixel units of multiple rows and columns, and then a first phase corresponding to the first side pixel subunit and a second phase corresponding to the second side pixel subunit in the pixel subunits of n rows and n columns included in the first pixel unit are obtained. For the second pixel unit that does not correspond to the preview image in the pixel units of multiple rows and columns, the second switch tubes in the pixel subunits of n rows and n columns included in the second pixel unit can be controlled to be closed, so that only the first pixel unit outputs phase information, and the second pixel unit does not output phase information.

[0070] In an embodiment of the present application, only the first pixel unit corresponding to the preview image among the multiple rows and columns of pixel units outputs phase information, while the second pixel unit not corresponding to the preview image among the multiple rows and columns of pixel units does not output phase information, which can improve the reading speed of the sensor and reduce power consumption.

[0071] The embodiment of the present application also provides an image sensor, including the pixel circuit provided by the embodiment of the present application.

[0072] The embodiment of the present application also provides a camera module, including the image sensor provided by the embodiment of the present application.

[0073] An embodiment of the present application also provides an electronic device, including the camera module provided in the embodiment of the present application.

[0074] The electronic device in the embodiment of the present application may be a terminal, or may be other devices other than a terminal. For example, the electronic device may be a mobile phone, a tablet computer, a laptop computer, a PDA, a vehicle-mounted electronic device, a mobile Internet device (MID), an augmented reality (AR) / virtual reality (VR) device, a robot, a wearable device, an ultra-mobile personal computer (UMPC), a netbook or a personal digital assistant (PDA), etc., and may also be a server, a network attached storage (NAS), a personal computer (PC), a television (TV), a teller machine or a self-service machine, etc., which is not specifically limited in the embodiment of the present application.

[0075] The electronic device in the embodiment of the present application may be an electronic device having an operating system. The operating system may be an Android operating system, an iOS operating system, or other possible operating systems, which are not specifically limited in the embodiment of the present application.

[0076] The embodiment of the present application also provides an automatic focusing method, which is applied to the electronic device provided in the embodiment of the present application.

[0077] Fig. 9 is a flow chart of an automatic focusing method provided in an embodiment of the present application. The automatic focusing method may include the following steps:

[0078] Step 901: Obtain a first phase corresponding to a first-side pixel sub-unit in pixel sub-units of n rows and n columns;

[0079] Step 902: Obtain a second phase corresponding to a second side pixel sub-unit in the pixel sub-units of n rows and n columns;

[0080] In some possible implementations of the embodiments of the present application, the first side pixel sub-unit and the second side pixel sub-unit in the embodiments of the present application may be pixel sub-units on opposite sides of n rows and n columns of pixel sub-units, for example, the first side is the upper side and the second side is the lower side; for another example, the first side is the left side and the second side is the right side.

[0081] The embodiment of the present application does not elaborate on the specific process of obtaining the first phase corresponding to the first side pixel sub-unit and the second phase corresponding to the second side pixel sub-unit in the pixel sub-unit of n rows and n columns. The specific process can refer to the above-mentioned process of obtaining the upper phase and the lower phase and obtaining the left phase and the right phase.

[0082] Step 903: determining a phase difference between the first phase and the second phase according to the first phase and the second phase;

[0083] Step 904: Control the camera of the electronic device to perform automatic focusing according to the phase difference.

[0084] After obtaining the first phase corresponding to the first side pixel sub-unit and the second phase corresponding to the second side pixel sub-unit, the phase difference between the first phase and the second phase can be determined; and then phase detection autofocus is performed based on the phase difference. The process of performing phase detection autofocus based on the phase difference can be referred to the description in the relevant technology, and the embodiments of the present application will not be described in detail here.

[0085] In an embodiment of the present application, by obtaining the first phase corresponding to the first side pixel subunit and the second phase corresponding to the second side pixel subunit in the pixel subunits of n rows and n columns, the phase difference between the first phase and the second phase is determined, and then phase detection autofocus is performed based on the phase difference. This can improve the focusing capability of the electronic device without affecting the power consumption of the electronic device.

[0086] In some possible implementations of the embodiments of the present application, step 901 may include: receiving a zoom input; in response to the zoom input, adjusting a preview image according to the zoom input; determining a first pixel unit corresponding to the preview image; obtaining a first phase corresponding to a first side pixel sub-unit among the pixel sub-units of n rows and n columns included in the first pixel unit; accordingly, step 902 may include: obtaining a second phase corresponding to a second side pixel sub-unit among the pixel sub-units of n rows and n columns included in the first pixel unit.

[0087] In some possible implementations of the embodiments of the present application, when zooming, the focal length of the lens changes, thereby changing the size of the preview image. At this time, a first pixel unit corresponding to the preview image is determined from the pixel units of multiple rows and columns, and then a first phase corresponding to the first side pixel subunit and a second phase corresponding to the second side pixel subunit in the pixel subunits of n rows and n columns included in the first pixel unit are obtained. For the second pixel unit that does not correspond to the preview image in the pixel units of multiple rows and columns, the second switch tubes in the pixel subunits of n rows and n columns included in the second pixel unit can be controlled to be closed, so that only the first pixel unit outputs phase information, and the second pixel unit does not output phase information.

[0088] In the embodiment of the present application, only the first phase corresponding to the first side pixel sub-unit and the second phase corresponding to the second side pixel sub-unit in the n rows and n columns of pixel sub-units included in the first pixel unit corresponding to the preview image in the pixel units of multiple rows and columns are obtained, without obtaining the phases of the pixel units that do not correspond to the preview image in the pixel units of multiple rows and columns, which can improve the reading speed of the sensor and reduce power consumption.

[0089] Fig.10 It is a schematic diagram of the hardware structure of an electronic device implementing an embodiment of the present application.

[0090] The electronic device 1000 includes but is not limited to: a radio frequency unit 1001, a network module 1002, an audio output unit 1003, an input unit 1004, a sensor 1005, a display unit 1006, a user input unit 1007, an interface unit 1008, a memory 1009, and a processor 1010 and other components.

[0091] Those skilled in the art will appreciate that the electronic device 1000 may also include a power source (such as a battery) for supplying power to each component, and the power source may be logically connected to the processor 1010 through a power management system, thereby implementing functions such as managing charging, discharging, and power consumption management through the power management system. Fig.10 The electronic device structure shown in the figure does not constitute a limitation on the electronic device. The electronic device may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently, which will not be described in detail here.

[0092] Among them, the electronic device 1000 in the embodiment of the present application includes the camera module provided in the embodiment of the present application, the camera module provided in the embodiment of the present application includes the image sensor provided in the embodiment of the present application; the image sensor provided in the embodiment of the present application includes the pixel circuit provided in the embodiment of the present application.

[0093] Processor 1010 is used to: obtain a first phase corresponding to a first side pixel sub-unit among pixel sub-units of n rows and n columns; obtain a second phase corresponding to a second side pixel sub-unit among pixel sub-units of n rows and n columns; determine a phase difference between the first phase and the second phase based on the first phase and the second phase; and control a camera of the electronic device to perform autofocus based on the phase difference.

[0094] In an embodiment of the present application, by obtaining the first phase corresponding to the first side pixel subunit and the second phase corresponding to the second side pixel subunit in the pixel subunits of n rows and n columns, the phase difference between the first phase and the second phase is determined, and then phase detection autofocus is performed based on the phase difference. This can improve the focusing capability of the electronic device without affecting the power consumption of the electronic device.

[0095] In some possible implementations of the embodiments of the present application, the processor 1010 is specifically used to: receive a zoom input; in response to the zoom input, adjust the preview image according to the zoom input; determine a first pixel unit corresponding to the preview image; obtain a first phase corresponding to a first side pixel sub-unit among the pixel sub-units of n rows and n columns included in the first pixel unit; obtain a second phase corresponding to a second side pixel sub-unit among the pixel sub-units of n rows and n columns included in the first pixel unit.

[0096] In the embodiment of the present application, only the first phase corresponding to the first side pixel sub-unit and the second phase corresponding to the second side pixel sub-unit in the n rows and n columns of pixel sub-units included in the first pixel unit corresponding to the preview image in the pixel units of multiple rows and columns are obtained, without obtaining the phases of the pixel units that do not correspond to the preview image in the pixel units of multiple rows and columns, which can improve the reading speed of the sensor and reduce power consumption.

[0097] It should be understood that in the embodiment of the present application, the input unit 1004 may include a graphics processor (Graphics Processing Unit, GPU) 10041 and a microphone 10042, and the graphics processor 10041 processes the image data of the static picture or video obtained by the image capture device (such as a camera) in the video capture mode or the image capture mode. The display unit 1006 may include a display panel 10061, and the display panel 10061 may be configured in the form of a liquid crystal display, an organic light emitting diode, etc. The user input unit 1007 includes a touch panel 10071 and at least one of other input devices 10072. The touch panel 10071 is also called a touch screen. The touch panel 10071 may include two parts: a touch detection device and a touch controller. Other input devices 10072 may include, but are not limited to, a physical keyboard, function keys (such as volume control keys, switch keys, etc.), a trackball, a mouse, and a joystick, which will not be repeated here.

[0098] The memory 1009 can be used to store software programs and various data. The memory 1009 may mainly include a first storage area for storing programs or instructions and a second storage area for storing data, wherein the first storage area may store an operating system, an application program or instructions required for at least one function (such as a sound playback function, an image playback function, etc.), etc. In addition, the memory 1009 may include a volatile memory or a non-volatile memory, or the memory 1009 may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), a static random access memory (SRAM), a dynamic random access memory (DRAM), a synchronous dynamic random access memory (SDRAM), a double data rate synchronous dynamic random access memory (DDRSDRAM), an enhanced synchronous dynamic random access memory (ESDRAM), a synchronous link dynamic random access memory (SLDRAM) and a direct memory bus random access memory (DRRAM). The memory 1009 in the embodiment of the present application includes but is not limited to these and any other suitable types of memory.

[0099] The processor 1010 may include one or more processing units; optionally, the processor 1010 integrates an application processor and a modem processor, wherein the application processor mainly processes operations related to an operating system, a user interface, and application programs, and the modem processor mainly processes wireless communication signals, such as a baseband processor. It is understandable that the modem processor may not be integrated into the processor 1010.

[0100] An embodiment of the present application also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, each process of the above-mentioned automatic focusing method embodiment is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0101] The processor is a processor in the electronic device described in the above embodiment. The readable storage medium includes a computer-readable storage medium, and examples of computer-readable storage media include non-transitory computer-readable media, such as a computer read-only memory ROM, a random access memory RAM, a magnetic disk or an optical disk.

[0102] An embodiment of the present application also provides a chip, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned autofocus method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0103] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0104] An embodiment of the present application also provides a computer program product, which is stored in a storage medium. The program product is executed by at least one processor to implement the various processes of the above-mentioned automatic focusing method embodiment and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0105] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0106] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a computer software product, which is stored in a storage medium (such as ROM / RAM, a disk, or an optical disk), and includes a number of instructions for a terminal (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0107] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A pixel circuit, characterized in that: The pixel circuit comprises: a plurality of rows and columns of pixel units and a plurality of signal readout units; The input ends of the plurality of signal readout units are electrically connected one by one to the plurality of rows of pixel units; The output ends of the plurality of signal readout units are electrically connected one by one to a plurality of analog-to-digital converters; the signal readout unit is used to read out the voltage signal corresponding to each row of pixel units to the analog-to-digital converter; Each pixel unit includes a first phase subunit, a second phase subunit and pixel subunits in n rows and n columns, wherein n is a positive integer greater than or equal to 2, and the pixel subunits included in the same pixel unit have the same color; The first end of the first phase subunit is connected to the first to the second The positive electrode of the photosensitive element included in the row pixel subunit is electrically connected; The first end of the second phase subunit is connected to the first The positive electrodes of the photosensitive elements included in the pixel sub-units in the nth row are electrically connected; A second end of the first phase subunit and a second end of the second phase subunit are electrically connected to the analog-to-digital converter.

2. The pixel circuit according to claim 1, characterized in that: The pixel subunit includes a first switch tube, a photosensitive element and a second switch tube; The cathode of the photosensitive element is electrically connected to the source of the first switch tube; The drain of the first switch tube is electrically connected to a signal readout unit corresponding to a pixel unit including the photosensitive element; The positive electrode of the photosensitive element is electrically connected to the drain electrode of the second switch tube; The source of the second switch tube is grounded.

3. The pixel circuit according to claim 1, characterized in that: The first phase subunit includes: a third switch tube and a first capacitor; the second phase subunit includes: a fourth switch tube and a second capacitor; The drain of the third switch tube is connected to the first to the The positive electrode of the photosensitive element of the row pixel subunit is electrically connected; The source of the third switch tube is electrically connected to the first electrode plate of the first capacitor; The drain of the fourth switch tube is connected to the The positive electrodes of the photosensitive elements of the n-th row of pixel sub-units are electrically connected; The source of the fourth switch tube is electrically connected to the first electrode plate of the second capacitor; The second plate of the first capacitor and the second plate of the second capacitor are grounded.

4. The pixel circuit according to claim 3, characterized in that: The first phase subunit further includes: a fifth switch tube; the second phase subunit further includes a sixth switch tube; The drain of the fifth switch tube and the drain of the sixth switch tube are respectively connected to a power source; The source of the fifth switch tube is electrically connected to the first electrode plate of the first capacitor; The source of the sixth switch tube is electrically connected to the first electrode plate of the second capacitor.

5. The pixel circuit according to claim 3, characterized in that: The first phase subunit further includes: a seventh switch tube; the second phase subunit further includes an eighth switch tube; The drain of the seventh switch tube and the drain of the eighth switch tube are respectively connected to a power source; The source of the seventh switch tube and the source of the eighth switch tube are electrically connected to the analog-to-digital converter respectively; The gate of the seventh switch tube is electrically connected to the first electrode plate of the first capacitor; The gate of the eighth switch tube is electrically connected to the first electrode plate of the second capacitor.

6. The pixel circuit according to claim 3, characterized in that: The first capacitor and the second capacitor are variable capacitors.

7. The pixel circuit according to claim 3, characterized in that: The pixel unit also includes a ninth switch tube; The drain of the ninth switch tube is electrically connected to the drain of the third switch tube; The source of the ninth switch tube is electrically connected to the drain of the fourth switch tube.

8. An image sensor, characterized in that: The image sensor comprises the pixel circuit according to any one of claims 1 to 7.

9. A camera module, characterized in that: The camera module includes the image sensor described in claim 8.

10. An electronic device, characterized in that: The electronic device includes the camera module described in claim 9.

11. An automatic focusing method, characterized in that: Applicable to the electronic device according to claim 10; the method comprising: Obtaining a first phase corresponding to a first-side pixel sub-unit in the pixel sub-units of n rows and n columns; Acquire a second phase corresponding to a second side pixel sub-unit in the pixel sub-units of n rows and n columns; Determining a phase difference between the first phase and the second phase according to the first phase and the second phase; According to the phase difference, the camera of the electronic device is controlled to perform automatic focusing.

12. The method according to claim 11, characterized in that The obtaining of the first phase corresponding to the first side pixel sub-unit in the pixel sub-units of n rows and n columns includes: Receive zoom input; In response to the zoom input, adjusting the preview image according to the zoom input; Determining a first pixel unit corresponding to the preview image; Acquire a first phase corresponding to a first-side pixel sub-unit among the pixel sub-units of n rows and n columns included in the first pixel unit; The obtaining of the second phase corresponding to the second side pixel sub-unit in the pixel sub-units of the n rows and n columns includes: A second phase corresponding to a second-side pixel sub-unit among the pixel sub-units of n rows and n columns included in the first pixel unit is obtained.

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