Pixel circuit, image sensor, camera module, equipment and image generation method

Abstract

The invention discloses a pixel circuit, an image sensor, a camera module, equipment and an image generation method, and belongs to the technical field of camera shooting. The pixel circuit comprises a plurality of rows and columns of pixel units and a plurality of signal reading units. The input ends of the plurality of signal reading units are electrically connected with the plurality of rows of pixel units one by one; the input ends of the plurality of signal reading units are electrically connected with the plurality of analog-to-digital converters one by one; each pixel unit comprises a calibration subunit, a compensation subunit and n rows and n columns of pixel subunits; the first end of the calibration subunit is electrically connected with the positive electrode of the photosensitive element included in the pixel subunit; the second end of the calibration subunit is electrically connected with the first analog-to-digital converter; the third end of the calibration subunit is electrically connected with the output end of the compensation subunit; the input end of the compensation subunit is electrically connected with the image processor; the compensation subunit is used for receiving the reference value sent by the image processor and calibrating the photosensitive value of each photosensitive element; the image processor is electrically connected with the analog-to-digital converters.

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 image generation method. Background Art

[0002] The electronic device industry, such as mobile phones and cameras, is highly competitive and is increasingly pursuing clearer images.

[0003] In the related art, in order to improve image clarity, a multi-pixel method is usually used to generate an image, for example, four-in-one, nine-in-one and sixteen-in-one. The generated image is a multiple Bayer image. When generating a multiple Bayer image, each pixel is output, and finally a multiple Bayer image is generated.

[0004] However, the image processor can only process Bayer images, and the multiple Bayer images need to be processed into Bayer images through a remosaic algorithm. However, due to the influence of crosstalk (Xtalk), when the multiple Bayer images are processed into Bayer images using the remosaic algorithm, the image clarity will decrease, resulting in unclear images. Summary of the invention

[0005] 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 image generation method that can improve image clarity.

[0006] 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;

[0007] The input ends of the plurality of signal readout units are electrically connected one by one to the plurality of rows of pixel units;

[0008] 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;

[0009] Each pixel unit includes a calibration subunit, a compensation subunit and pixel subunits of 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;

[0010] The first end of the calibration subunit is electrically connected to the positive electrode of the photosensitive element included in the pixel subunit;

[0011] The second end of the calibration subunit is electrically connected to the first analog-to-digital converter, wherein the first analog-to-digital converter is an analog-to-digital converter electrically connected to the row where the pixel units are located;

[0012] The third terminal of the calibration subunit is electrically connected to the output terminal of the compensation subunit;

[0013] The input end of the compensation subunit is electrically connected to the image processor; the compensation subunit is used to receive a reference value for calibrating the light sensitivity value of each photosensitive element sent by the image processor, and calibrate the light sensitivity value of each photosensitive element;

[0014] The image processor is electrically connected to the plurality of analog-to-digital converters.

[0015] In a second aspect, an embodiment of the present application provides an image sensor, including:

[0016] The pixel circuit provided by the embodiment of the present application.

[0017] In a third aspect, an embodiment of the present application provides a camera module, including:

[0018] An image sensor provided in an embodiment of the present application.

[0019] In a fourth aspect, an embodiment of the present application provides an electronic device, including:

[0020] The camera module provided in the embodiment of the present application.

[0021] A fifth method, an embodiment of the present application provides an image generation method, which is applied to the electronic device provided in an embodiment of the present application, and the method includes:

[0022] Obtaining the light sensitivity value of each pixel sub-unit in the pixel sub-units of n rows and n columns;

[0023] Determining a reference value for calibrating the light sensitivity value of the pixel subunit according to the light sensitivity value;

[0024] The sensitivity value of each pixel sub-unit is calibrated according to the reference value to obtain the calibrated n 2 times the Bayer image.

[0025] 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; 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 plurality of signal readout units are electrically connected one by one with the plurality of analog-to-digital converters; 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 calibration subunit, a compensation subunit and pixel subunits of 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; a first end of the calibration subunit is electrically connected to the positive electrode of the photosensitive element included in the pixel subunit; a second end of the calibration subunit is electrically connected to the first analog-to-digital converter, wherein the first analog-to-digital converter is an analog-to-digital converter electrically connected to the row where the pixel unit is located; a third end of the calibration subunit is electrically connected to the output end of the compensation subunit; an input end of the compensation subunit is electrically connected to an image processor; the compensation subunit is used to receive a reference value for calibrating the photosensitivity value of each photosensitive element sent by the image processor, and calibrate the photosensitivity value of each photosensitive element; the image processor is electrically connected to the plurality of analog-to-digital converters. The light sensitivity value of each photosensitive element is calibrated by the electrical signal of the positive electrode of the photosensitive element, and the calibrated n 2 The Bayer image can eliminate the influence of crosstalk and improve image clarity. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic diagram of the structure of a pixel circuit provided in an embodiment of the present application;

[0027] Figure 2 This is a schematic diagram of the first structure of a pixel unit provided in an embodiment of the present application;

[0028] Figure 3 is a schematic diagram of a second structure of a pixel unit provided in an embodiment of the present application;

[0029] Figure 4 is a third structural schematic diagram of a pixel unit provided in an embodiment of the present application;

[0030] Figure 5 is a fourth structural schematic diagram of a pixel unit provided in an embodiment of the present application;

[0031] Figure 6 is a fifth structural schematic diagram of a pixel unit provided in an embodiment of the present application;

[0032] Figure 7 is a schematic diagram of a specific structure of a pixel unit provided in an embodiment of the present application;

[0033] Figure 8 is a flowchart of an image generation method according to an embodiment of the present application;

[0034] Fig. 9It is a schematic diagram of the hardware structure of an electronic device implementing an embodiment of the present application. DETAILED DESCRIPTION

[0035] 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.

[0036] 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.

[0037] The pixel circuit, image sensor, camera module, device and image generation 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.

[0038] 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 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, the multiple analog-to-digital converters are connected to the image processor, and the image processor generates an image based on the digital signal generated by the analog-to-digital converter.

[0039] 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 input ends of the plurality of signal readout units 12 are electrically connected one by one with the plurality of rows of pixel units 11; the plurality of signal readout units 12 are electrically connected one by one with the plurality of analog-to-digital converters 200; the image processor 300 is electrically connected with the plurality of analog-to-digital converters 200; the analog-to-digital converter 200 converts the sampled voltage signal of each row of pixel units into a digital signal, and the image processor 300 generates an image according to the digital signal generated by the analog-to-digital converter 200.

[0040] In some possible implementations of the embodiments of the present application, each pixel unit in the embodiments of the present application includes a calibration subunit, a compensation subunit and pixel subunits of 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; a first end of the calibration subunit is electrically connected to the positive electrode of the photosensitive element included in the pixel subunit; a second end of the calibration subunit is electrically connected to the first analog-to-digital converter, wherein the first analog-to-digital converter is an analog-to-digital converter electrically connected to the row where the pixel unit is located; a third end of the calibration subunit is electrically connected to the output end of the compensation subunit; an input end of the compensation subunit is electrically connected to an image processor; the compensation subunit is used to receive a reference value sent by the image processor for calibrating the photosensitivity value of each photosensitive element, and calibrate the photosensitivity value of each photosensitive element; the image processor is electrically connected to multiple analog-to-digital converters.

[0041] 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.

[0042] The colors corresponding to the pixel sub-units included in the same pixel unit may be red, red-green, cyan, or blue.

[0043] 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 includes a calibration subunit 112, a compensation subunit 113, and n rows and n columns of pixel subunits 111. The first end of the calibration subunit 112 is electrically connected to the positive electrode of the photosensitive element PD included in the pixel subunit 111; the second end of the calibration subunit 112 is electrically connected to the analog-to-digital converter 200 electrically connected to the row where the pixel unit 11 is located; the third end of the calibration subunit 112 is electrically connected to the output end of the compensation subunit 113; the input end of the compensation subunit 113 is electrically connected to the image processor 300; the compensation subunit 113 is used to receive the reference value for calibrating the photosensitivity value of each photosensitive element sent by the image processor 300, and calibrate the photosensitivity value of each photosensitive element PD; the image processor 300 is electrically connected to the analog-to-digital converter 200.

[0044] 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 first signal readout unit, wherein the first signal readout unit is a signal readout unit electrically connected 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.

[0045] 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 electrically connected 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.

[0046] In some possible implementations of the embodiments of the present application, the calibration subunit may include a third switching tube and a first capacitor; the drain of the third switching tube is electrically connected to the positive electrode of the photosensitive element of the pixel subunit; the source of the third switching tube is electrically connected to the first plate of the first capacitor, the output end of the compensation subunit and the analog-to-digital converter respectively; the second plate of the first capacitor is grounded.

[0047] 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 calibration subunit 112, the calibration subunit 112 includes a third switch tube TG3 and a first capacitor C1. The drain of the third switch tube TG3 is electrically connected to the positive electrode of the photosensitive element PD of the pixel subunit 111; the source of the third switch tube TG3 is electrically connected to the first plate of the first capacitor C1; the output end of the compensation subunit 113 is electrically connected to the analog-to-digital converter 200; and the second plate of the first capacitor C1 is grounded.

[0048] In some possible implementations of the embodiments of the present application, the calibration subunit may further include: a fourth switch tube; the drain of the fourth switch tube is connected to the power supply; and the source of the fourth switch tube is electrically connected to the first plate of the first capacitor.

[0049] 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 calibration subunit 112 includes a third switch tube TG3, a first capacitor C1 and a fourth switch tube TG4. The drain of the third switch tube TG3 is electrically connected to the positive electrode of the photosensitive element PD of the pixel subunit 111; the source of the third switch tube TG3 is electrically connected to the first plate of the first capacitor C1, the source of the fourth switch tube TG4, the output end of the compensation subunit 113 and the analog-to-digital converter 200 respectively; the drain of the fourth switch tube is connected to the power supply VDD; the second plate of the first capacitor C1 is grounded.

[0050] When the fourth switch tube TG4 is turned on, the first capacitor C1 is cleared.

[0051] In some possible implementations of the embodiments of the present application, the calibration subunit may also include: a signal amplifier and a row selector; the drain of the signal amplifier is connected to the power supply; the source of the signal amplifier is electrically connected to the drain of the row selector; the gate of the signal amplifier is electrically connected to the first plate of the first capacitor; the source of the row selector is electrically connected to the analog-to-digital converter.

[0052] 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 figure, the calibration subunit 112 includes a third switch tube TG3, a first capacitor C1, a signal amplifier TG5 and a row selector TG6. The drain of the third switch tube TG3 is electrically connected to the positive electrode of the photosensitive element PD of the pixel subunit 111; the source of the third switch tube TG3 is electrically connected to the first plate of the first capacitor C1, the gate of the signal amplifier TG5 and the output end of the compensation subunit 113 respectively; the second plate of the first capacitor C1 is grounded; the drain of the signal amplifier TG5 is connected to the power supply VDD; the source of the signal amplifier TG5 is electrically connected to the drain of the row selector TG6; the source of the row selector TG6 is electrically connected to the analog-to-digital converter 200.

[0053] The voltage signal of the first capacitor C1 is amplified by the signal amplifier TG5 and the row selector TG6 and then transmitted to the analog-to-digital converter for reading.

[0054] In some possible implementations of the embodiment of the present application, the first capacitor in the embodiment of the present application is a variable capacitor.

[0055] Figure 7 It is a specific structural schematic diagram of a pixel unit provided in an embodiment of the present application.

[0056] exist Figure 7 In the embodiment, the pixel unit 11 includes a calibration subunit 112, a compensation subunit 113 and 2 rows and 2 columns of pixel subunits 111. The pixel subunit 111 includes a first switch tube TG1, a second switch tube TG2 and a photosensitive element PD; the calibration subunit 112 includes a third switch tube TG3, a first capacitor C1, a fourth switch tube TG4, a signal amplifier TG5 and a row selector TG6; the signal readout unit 12 includes a reset transistor RST, a parasitic capacitor FD, a signal amplifier SF and a row selector SET.

[0057] The pixel sub-units of 2 rows and 2 columns include an upper left pixel sub-unit, an upper right pixel sub-unit, a lower left pixel sub-unit, and a lower right pixel sub-unit.

[0058] 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).

[0059] 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 VDD, 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 DC 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. The analog-to-digital converter 200 is connected to the image processor 300.

[0060] The drain of the third switch tube TG3 is electrically connected to the positive electrode of the photosensitive element PD of each row of pixel sub-units; the source of the third switch tube TG3 is electrically connected to the first plate of the first capacitor C1, the source of the fourth switch tube TG4, the output end of the compensation sub-unit 113 and the gate of the signal amplifier TG5 respectively; the drain of the fourth switch tube TG4 and the drain of the signal amplifier TG5 are electrically connected to the power supply VDD; the source of the signal amplifier TG5 is electrically connected to the drain of the row selector TG6; the source of the row selector TG6 is electrically connected to the analog-to-digital converter 200.

[0061] When the pixel is exposed, the reset transistor RST, the fourth switch tube TG4 and each pixel sub-unit including the first switch tube TG1 are turned on to clear the first capacitor C1 and the parasitic capacitor FD. The electron-hole pairs generated by light irradiation will separate due to the presence of the electric field of the photosensitive element PD, and the electrons will move to the N area and the holes will 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 a second time through the signal amplifier SF and the row selector SET, and the signal read at this time is stored as a 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 sampled by analog amplification and analog-to-digital converter 200 to obtain a digital signal corresponding to the light signal. The analog-to-digital converter 200 sends the digital signal corresponding to the light signal of each photosensitive element to the image processor 300. The image processor 300 averages the digital signals corresponding to the photosensitive elements included in each pixel unit to obtain a reference value of the corresponding pixel unit, wherein the digital signal corresponding to the light signal of each photosensitive element is the photosensitivity value of each pixel sub-unit.

[0062] For example, assuming that the light-sensitivity value of the photosensitive element included in the upper left pixel subunit is 85 least significant bits (LSB), the light-sensitivity value of the photosensitive element included in the upper right pixel subunit is 110 LSB, the light-sensitivity value of the photosensitive element included in the lower left pixel subunit is 90 LSB, and the light-sensitivity value of the photosensitive element included in the lower right pixel subunit is 75 LSB, then the reference value for calibrating the light-sensitivity value of the photosensitive element included in the pixel subunit is (85+110+90+75) / 4=90 LSB. Then the light-sensitivity value of the photosensitive element included in the pixel subunit is calibrated to 90 LSB.

[0063] Exemplarily, when the light-sensing value of the photosensitive element included in the upper left pixel subunit is calibrated, the second switch tube TG2 at the positive end of the photosensitive element included in the upper left pixel subunit is disconnected, the third switch tube TG3 and the fourth switch tube TG4 are closed, and the positively charged holes of the photosensitive element included in the upper left pixel subunit are all transferred to the first capacitor C1, and the calibration parameter corresponding to the photosensitive element included in the upper left pixel subunit is 90LSB / 85LSB=1.059. Assuming that the original capacitance value of the first capacitor C1 is 1 microfarad (uf), the capacitance value of the first capacitor C1 is adjusted to 1 / 1.059=0.944uf by the compensation subunit. After the capacitance value of the first capacitor C1 becomes 0.944uf, the actual voltage of the first capacitor C1 is 1.059 times the original voltage. The voltage signal of the first capacitor C1 is transmitted to the analog-to-digital converter 200 through the signal amplifier TG5 and the row selector TG6 for reading, and the light-sensing value of the photosensitive element included in the upper left pixel subunit after calibration is 90LSB.

[0064] When the light-sensing value of the photosensitive element included in the upper right pixel subunit is calibrated, the fourth switch tube TG4 is disconnected, the first capacitor C1 is cleared, the third switch tube TG3 is disconnected, and the second switch tube TG2 at the positive end of the photosensitive element included in the upper left pixel subunit is closed. Then, the second switch tube TG2 at the positive end of the photosensitive element included in the upper right pixel subunit is disconnected, and the third switch tube TG3 and the fourth switch tube TG4 are closed. The positively charged holes of the photosensitive element included in the upper right pixel subunit are all transferred to the first capacitor C1. The calibration parameter corresponding to the photosensitive element included in the upper right pixel subunit is 90LSB / 110LSB=0.82. Assuming that the original capacitance value of the first capacitor C1 is 1uf, the capacitance value of the first capacitor C1 is adjusted to 1 / 0.82=1.22uf through the compensation subunit. After the capacitance value of the first capacitor C1 becomes 1.22uf, the actual voltage of the first capacitor C1 is 0.82 times the original voltage. The voltage signal of the first capacitor C1 is transmitted to the analog-to-digital converter 200 for reading through the signal amplifier TG5 and the row selector TG6, and the calibrated light-sensing value 90LSB of the light-sensing element included in the upper right pixel subunit is obtained.

[0065] When the light-sensing value of the photosensitive element included in the lower left pixel subunit is calibrated, the fourth switch tube TG4 is disconnected, the first capacitor C1 is cleared, the third switch tube TG3 is disconnected, and the second switch tube TG2 at the positive end of the photosensitive element included in the upper right pixel subunit is closed. Then, the second switch tube TG2 at the positive end of the photosensitive element included in the lower left pixel subunit is disconnected, and the third switch tube TG3 and the fourth switch tube TG4 are closed. The positively charged holes of the photosensitive element included in the lower left pixel subunit are all transferred to the first capacitor C1, and the calibration parameter corresponding to the photosensitive element included in the lower left pixel subunit is 90LSB / 90LSB=1. Assuming that the original capacitance value of the first capacitor C1 is 1uf, the capacitance value of the first capacitor C1 is adjusted to 1 / 1=1uf through the compensation subunit. The capacitance value of the first capacitor C1 remains unchanged, and the actual voltage of the first capacitor C1 is 1 times the original voltage. The voltage signal of the first capacitor C1 is transmitted to the analog-to-digital converter 200 for reading through the signal amplifier TG5 and the row selector TG6, and the calibrated light-sensing value 90LSB of the light-sensing element included in the lower left pixel sub-unit is obtained.

[0066] When the light-sensing value of the photosensitive element included in the lower right pixel subunit is calibrated, the fourth switch tube TG4 is disconnected, the first capacitor C1 is cleared, the third switch tube TG3 is disconnected, and the second switch tube TG2 at the positive end of the photosensitive element included in the lower left pixel subunit is closed. Then, the second switch tube TG2 at the positive end of the photosensitive element included in the lower right pixel subunit is disconnected, and the third switch tube TG3 and the fourth switch tube TG4 are closed. The positively charged holes of the photosensitive element included in the lower right pixel subunit are all transferred to the first capacitor C1. The calibration parameter corresponding to the photosensitive element included in the lower right pixel subunit is 90LSB / 75LSB=1.2. Assuming that the original capacitance value of the first capacitor C1 is 1uf, the capacitance value of the first capacitor C1 is adjusted to 1 / 1.2=0.83uf through the compensation subunit. After the capacitance value of the first capacitor C1 becomes 0.83uf, the actual voltage of the first capacitor C1 is 1.2 times the original voltage. The voltage signal of the first capacitor C1 is transmitted to the analog-to-digital converter 200 for reading through the signal amplifier TG5 and the row selector TG6, and the calibrated light-sensing value 90LSB of the light-sensing element included in the lower right pixel subunit is obtained.

[0067] In the embodiment of the present application, the photosensitivity value of each pixel sub-unit is calibrated by the electrical signal of the positive electrode of the photosensitive element, so that the influence of crosstalk can be eliminated, and thus when the multiple Bayer image is processed into a Bayer image using the remosaic algorithm, the image clarity can be avoided from being reduced and the image clarity can be improved.

[0068] The positive and negative electrodes of the pixel subunit in the embodiment of the present application can output two voltage signals. While not affecting the normal pixel function, a high-resolution image can be obtained after calibrating the crosstalk, which can effectively increase the number of real photosensitive pixels. There will be no image blur caused by the user moving or the scene moving when taking pictures, and the image quality can be improved.

[0069] The embodiment of the present application also provides an image sensor, including the pixel circuit provided by the embodiment of the present application.

[0070] The embodiment of the present application also provides a camera module, including the image sensor provided by the embodiment of the present application.

[0071] An embodiment of the present application also provides an electronic device, including the camera module provided by the embodiment of the present application.

[0072] 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.

[0073] 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.

[0074] The embodiment of the present application also provides an image generating method, which is applied to the electronic device provided in the embodiment of the present application.

[0075] Figure 8 : is a flow chart of an image generation method provided in an embodiment of the present application. The image generation method may include the following steps:

[0076] Step 801: obtaining the light sensitivity value of each pixel sub-unit in the pixel sub-units of n rows and n columns;

[0077] Step 802: Determine a reference value for calibrating the light sensitivity value of the pixel subunit according to the light sensitivity value;

[0078] Step 803: Calibrate the light sensitivity value of each pixel sub-unit according to the reference value to obtain the calibrated n 2 times the Bayer image.

[0079] In some possible implementations of the embodiments of the present application, step 802 may include: determining an average value of the photosensitivity values ​​of the pixel sub-units in the pixel sub-units of n rows and n columns; and using the average value as a reference value corresponding to the pixel sub-units of n rows and n columns.

[0080] In some possible implementations of the embodiments of the present application, step 803 may include: calibrating the photosensitivity value of each pixel sub-unit to a reference value.

[0081] Exemplarily, the following is an example of a pixel subunit with 2 rows and 2 columns including an upper left pixel subunit, an upper right pixel subunit, a lower left pixel subunit, and a lower right pixel subunit. Assuming that the light sensitivity value of the photosensitive element included in the upper left pixel subunit is 85 least significant bits (LSB), the light sensitivity value of the photosensitive element included in the upper right pixel subunit is 110LSB, the light sensitivity value of the photosensitive element included in the lower left pixel subunit is 90LSB, and the light sensitivity value of the photosensitive element included in the lower right pixel subunit is 75LSB, then the reference value for calibrating the light sensitivity value of the photosensitive element included in the pixel subunit is (85+110+90+75) / 4=90LSB. Then, the light sensitivity value of the photosensitive element included in the pixel subunit is calibrated to 90LSB.

[0082] In some possible implementations of the embodiments of the present application, calibrating the photosensitivity value of each pixel sub-unit to a reference value may include: calculating, for a first pixel sub-unit, a ratio of the reference value to the photosensitivity value of the first pixel sub-unit, wherein the first pixel sub-unit is any one of the pixel sub-units in n rows and n columns; disconnecting a second switch tube electrically connecting the first pixel sub-unit to the positive electrode of a photosensitive element; closing a third switch tube included in a calibration sub-unit; and adjusting the capacitance value of a first capacitor included in the calibration sub-unit to one-third of the ratio of an original capacitance value of the first capacitor through a compensation sub-unit, so as to calibrate the photosensitivity value of the first pixel sub-unit to a reference value.

[0083] Exemplarily, the following is an example of a pixel subunit with 2 rows and 2 columns including an upper left pixel subunit, an upper right pixel subunit, a lower left pixel subunit, and a lower right pixel subunit. The photosensitivity value of the photosensitive element included in the upper left pixel subunit is 85LSB, the photosensitivity value of the photosensitive element included in the upper right pixel subunit is 110LSB, the photosensitivity value of the photosensitive element included in the lower left pixel subunit is 90LSB, and the photosensitivity value of the photosensitive element included in the lower right pixel subunit is 75LSB. The reference value corresponding to the pixel subunit with 2 rows and 2 columns is (85+110+90+75) / 4=90LSB.

[0084] When calibrating the photosensitivity of the photosensitive element included in the upper left pixel subunit, the second switch tube at the positive end of the photosensitive element included in the upper left pixel subunit is disconnected, and the third switch tube and the fourth switch tube are closed. The positively charged holes of the photosensitive element included in the upper left pixel subunit are all transferred to the first capacitor, and the calibration parameter corresponding to the photosensitive element included in the upper left pixel subunit is 90LSB / 85LSB=1.059. Assuming that the original capacitance value of the first capacitor is 1uf, the capacitance value of the first capacitor is adjusted to 1 / 1.059=0.944uf through the compensation subunit. After the capacitance value of the first capacitor becomes 0.944uf, the actual voltage of the first capacitor is 1.059 times the original voltage. The voltage signal of the first capacitor is transmitted to the analog-to-digital converter through the signal amplifier and the row selector for reading, and the photosensitivity value of the photosensitive element included in the upper left pixel subunit after calibration is 90LSB.

[0085] When the light-sensing value of the photosensitive element included in the upper right pixel subunit is calibrated, the fourth switch tube is disconnected, the first capacitor is cleared, the third switch tube is disconnected, and the second switch tube at the positive end of the photosensitive element included in the upper left pixel subunit is closed. Then, the second switch tube at the positive end of the photosensitive element included in the upper right pixel subunit is disconnected, and the third switch tube and the fourth switch tube are closed. The positively charged holes of the photosensitive element included in the upper right pixel subunit are all transferred to the first capacitor, and the calibration parameter corresponding to the photosensitive element included in the upper right pixel subunit is 90LSB / 110LSB=0.82. Assuming that the original capacitance value of the first capacitor is 1uf, the capacitance value of the first capacitor is adjusted to 1 / 0.82=1.22uf by the compensation subunit. After the capacitance value of the first capacitor becomes 1.22uf, the actual voltage of the first capacitor is 0.82 times the original voltage. The voltage signal of the first capacitor is transmitted to the analog-to-digital converter through the signal amplifier and the row selector for reading, and the light-sensing value of the photosensitive element included in the upper right pixel subunit after calibration is 90LSB.

[0086] When the light-sensing value of the photosensitive element included in the lower left pixel subunit is calibrated, the fourth switch tube is disconnected, the first capacitor is cleared, the third switch tube is disconnected, and the second switch tube at the positive end of the photosensitive element included in the upper right pixel subunit is closed. Then, the second switch tube at the positive end of the photosensitive element included in the lower left pixel subunit is disconnected, and the third switch tube and the fourth switch tube are closed. The positively charged holes of the photosensitive element included in the lower left pixel subunit are all transferred to the first capacitor, and the calibration parameter corresponding to the photosensitive element included in the lower left pixel subunit is 90LSB / 90LSB=1. Assuming that the original capacitance value of the first capacitor is 1uf, the capacitance value of the first capacitor C1 is adjusted to 1 / 1=1uf through the compensation subunit. The capacitance value of the first capacitor remains unchanged, and the actual voltage of the first capacitor is 1 times the original voltage. The voltage signal of the first capacitor is transmitted to the analog-to-digital converter through the signal amplifier and the row selector for reading, and the light-sensing value of the photosensitive element included in the lower left pixel subunit after calibration is 90LSB.

[0087] When the light-sensing value of the photosensitive element included in the lower right pixel subunit is calibrated, the fourth switch tube is disconnected, the first capacitor is cleared, the third switch tube is disconnected, and the second switch tube at the positive end of the photosensitive element included in the lower left pixel subunit is closed. Then, the second switch tube at the positive end of the photosensitive element included in the lower right pixel subunit is disconnected, and the third switch tube and the fourth switch tube are closed. The positively charged holes of the photosensitive element included in the lower right pixel subunit are all transferred to the first capacitor. The calibration parameter corresponding to the photosensitive element included in the lower right pixel subunit is 90LSB / 75LSB=1.2. Assuming that the original capacitance value of the first capacitor is 1uf, the capacitance value of the first capacitor C1 is adjusted to 1 / 1.2=0.83uf through the compensation subunit. After the capacitance value of the first capacitor becomes 0.83uf, the actual voltage of the first capacitor is 1.2 times the original voltage. The voltage signal of the first capacitor is transmitted to the analog-to-digital converter through the signal amplifier and the row selector for reading, and the light-sensing value of the photosensitive element included in the lower right pixel subunit after calibration is 90LSB.

[0088] In the embodiment of the present application, the photosensitivity value of each pixel sub-unit is calibrated by the electrical signal of the positive electrode of the photosensitive element, so that the influence of crosstalk can be eliminated, and thus when the multiple Bayer image is processed into a Bayer image using the remosaic algorithm, the image clarity can be avoided from being reduced and the image clarity can be improved.

[0089] Fig. 9 It is a schematic diagram of the hardware structure of an electronic device implementing an embodiment of the present application.

[0090] The electronic device 900 includes but is not limited to: a radio frequency unit 901, a network module 902, an audio output unit 903, an input unit 904, a sensor 905, a display unit 906, a user input unit 907, an interface unit 908, a memory 909, and a processor 910 and other components.

[0091] Those skilled in the art will appreciate that the electronic device 900 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 910 through a power management system, thereby implementing functions such as managing charging, discharging, and power consumption management through the power management system. Fig. 9 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 900 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 910 is used to: obtain the photosensitivity value of each pixel sub-unit in the pixel sub-units of n rows and n columns; determine a reference value for calibrating the photosensitivity value of the pixel sub-unit according to the photosensitivity value; calibrate the photosensitivity value of each pixel sub-unit according to the reference value to obtain a calibrated n2-fold Bayer image.

[0094] In the embodiment of the present application, by calibrating the photosensitivity value of each pixel sub-unit, the influence of crosstalk can be eliminated, and thus when the multiple Bayer image is processed into a Bayer image using a remosaic algorithm, a decrease in image clarity can be avoided and image clarity can be improved.

[0095] It should be understood that in the embodiment of the present application, the input unit 904 may include a graphics processor (Graphics Processing Unit, GPU) 9041 and a microphone 9042, and the graphics processor 9041 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 906 may include a display panel 9061, and the display panel 9061 may be configured in the form of a liquid crystal display, an organic light emitting diode, etc. The user input unit 907 includes a touch panel 9071 and at least one of other input devices 9072. The touch panel 9071 is also called a touch screen. The touch panel 9071 may include two parts: a touch detection device and a touch controller. Other input devices 9072 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.

[0096] The memory 909 can be used to store software programs and various data. The memory 909 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 909 may include a volatile memory or a non-volatile memory, or the memory 909 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 909 in the embodiment of the present application includes but is not limited to these and any other suitable types of memory.

[0097] The processor 910 may include one or more processing units; optionally, the processor 910 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 910.

[0098] 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, the various processes of the above-mentioned image generation method embodiment are implemented and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0099] 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.

[0100] 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 image generation method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0101] 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.

[0102] 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 image generation method embodiment and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0103] 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.

[0104] 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.

[0105] 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 input ends of 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 converters; Each pixel unit includes a calibration subunit, a compensation subunit and pixel subunits of 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 calibration subunit is electrically connected to the positive electrode of the photosensitive element included in the pixel subunit; The second end of the calibration subunit is electrically connected to a first analog-to-digital converter, wherein the first analog-to-digital converter is an analog-to-digital converter electrically connected to the row where the pixel units are located; The third terminal of the calibration subunit is electrically connected to the output terminal of the compensation subunit; The input end of the compensation subunit is electrically connected to the image processor; the compensation subunit is used to receive the reference value for calibrating the photosensitivity value of each photosensitive element sent by the image processor, and calibrate the photosensitivity value of each photosensitive element; The image processor is electrically connected to the plurality of analog-to-digital converters.

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 first signal readout unit, wherein the first signal readout unit is a signal readout unit electrically connected 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 calibration subunit includes: a third switch tube and a first capacitor; The drain of the third switch tube is electrically connected to the positive electrode of the photosensitive element of the pixel subunit; The source of the third switch tube is electrically connected to the first plate of the first capacitor, the output end of the compensation subunit and the analog-to-digital converter respectively; The second plate of the first capacitor is grounded.

4. The pixel circuit according to claim 3, characterized in that: The calibration subunit further includes: a fourth switch tube; The drain of the fourth switch tube is connected to the power supply; The source of the fourth switch tube is electrically connected to the first plate of the first capacitor.

5. The pixel circuit according to claim 3, characterized in that: The calibration subunit further includes: a signal amplifier and a row selector; The drain of the signal amplifier is connected to a power supply; The source of the signal amplifier is electrically connected to the drain of the row selector; The gate of the signal amplifier is electrically connected to the first plate of the first capacitor; The source of the row selector is electrically connected to the first analog-to-digital converter.

6. The pixel circuit according to claim 3, characterized in that: The first capacitor is a variable capacitor.

7. An image sensor, characterized in that: The image sensor comprises the pixel circuit according to any one of claims 1 to 6.

8. A camera module, characterized in that: The camera module includes the image sensor described in claim 7.

9. An electronic device, characterized in that: The electronic device includes the camera module described in claim 8.

10. An image generation method, characterized in that: Applicable to the electronic device according to claim 9; the method comprising: Obtaining the light sensitivity value of each pixel sub-unit in the n rows and n columns of pixel sub-units; Determining a reference value for calibrating the light sensitivity value of the pixel subunit according to the light sensitivity value; The light sensitivity value of each pixel sub-unit is calibrated according to the reference value to obtain the calibrated n 2 times the Bayer image.

11. The method according to claim 10, characterized in that The step of determining a reference value for calibrating the light sensitivity value of the pixel subunit according to the light sensitivity value includes: Determine an average value of the light sensitivity values ​​of the pixel sub-units in the pixel sub-units of n rows and n columns; The average value is used as the reference value corresponding to the pixel sub-units of the n rows and n columns.

12. The method according to claim 10, characterized in that The calibrating the light sensitivity value of each pixel sub-unit according to the reference value includes: The photosensitivity value of each pixel sub-unit is calibrated to the reference value.

13. The method according to claim 12, characterized in that The step of calibrating the light sensitivity value of each pixel sub-unit to the reference value includes: For a first pixel sub-unit, calculating a ratio of the reference value to a light-sensitive value of the first pixel sub-unit, wherein the first pixel sub-unit is any one of the pixel sub-units in the n rows and n columns; A second switch tube that disconnects the first pixel subunit from being electrically connected to the positive electrode of the photosensitive element; Closing the third switch tube included in the calibration subunit; The capacitance value of the first capacitor included in the calibration subunit is adjusted to one of the ratio of the original capacitance value of the first capacitor by the compensation subunit, so as to calibrate the photosensitivity value of the first pixel subunit to the reference value.

Images