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

Abstract

The application discloses a pixel circuit, an image sensor, a camera module, an 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 readout units; the input ends of the plurality of signal readout units are electrically connected with the plurality of rows of pixel units one by one; the input ends of the plurality of signal readout units are electrically connected with a 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 a photosensitive element included in the pixel subunit; the second end of the calibration subunit is electrically connected with a 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 an image processor; the compensation subunit is used for receiving a reference value sent by the image processor and calibrating the photosensitive value of each photosensitive element; and the image processor is electrically connected with the plurality of analog-to-digital converters.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of camera technology, and particularly relates to a pixel circuit, an image sensor, a camera module, a device and an image generation method. BACKGROUND

[0002] The electronic device industry such as mobile phones and cameras is highly competitive, and more and more clear images are pursued for shooting.

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

[0004] However, the image processor can only process the Bayer image, and the multiple Bayer image needs to be processed into the Bayer image by a remosaic algorithm. However, due to the influence of cross talk (Xtalk), when the multiple Bayer image is processed into the Bayer image by the remosaic algorithm, the image clarity will decrease, resulting in an unclear image. SUMMARY

[0005] The purpose of the embodiments of the application is to provide a pixel circuit, an image sensor, a camera module, a device and an image generation method, which can improve the image clarity.

[0006] In a first aspect, the embodiments of the application provide a pixel circuit, comprising: a plurality of rows and a plurality of 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 a plurality of analog-to-digital converters; the signal readout unit is configured to read out a voltage signal corresponding to each row of pixel units to the analog-to-digital converter;

[0009] Each pixel unit comprises a calibration subunit, a compensation 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 correspond to the same color;

[0010] The first end of the calibration subunit is electrically connected to the positive electrode of the light sensing 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 in which the pixel unit is located;

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

[0013] An input end of the compensation sub-unit is electrically connected with the image processor; the compensation sub-unit is configured to receive a reference value for calibrating the photosensitive value of each photosensitive element sent by the image processor, and calibrate the photosensitive value of each photosensitive element;

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

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

[0016] The pixel circuit provided in the embodiments of the present application.

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

[0018] The image sensor provided in the embodiments of the present application.

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

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

[0021] In a fifth aspect, an embodiment of the present application provides an image generation method, applied to the electronic device provided in the embodiments of the present application, and the method comprises:

[0022] Obtaining a photosensitive value of each pixel sub-unit in n rows and n columns of pixel sub-units;

[0023] According to the photosensitive value, determining a reference value for calibrating the photosensitive value of the pixel sub-unit;

[0024] According to the reference value, calibrating the photosensitive value of each pixel sub-unit to obtain a calibrated n 2 times Bayer image.

[0025] In the embodiment of the present application, the pixel circuit includes a plurality of pixel units in multiple rows and multiple columns 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 pixel units in multiple rows; the plurality of signal readout units are electrically connected one by one with a plurality of analog-to-digital converters; the signal readout units are configured to read out the voltage signals corresponding to each row of pixel units to the analog-to-digital converters; each pixel unit includes a calibration subunit, a compensation subunit, and n rows and n columns of pixel subunits, where n is a positive integer greater than or equal to 2, and the pixel subunits included in the same pixel unit correspond to the same color; the first end of the calibration subunit is electrically connected with the anode of a photosensitive element included in the pixel subunit; the second end of the calibration subunit is electrically connected with a first analog-to-digital converter, where the first analog-to-digital converter is an analog-to-digital converter electrically connected with the row in which the pixel unit is located; 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 an image processor; the compensation subunit is configured to receive a reference value for calibrating the photosensitive value of each photosensitive element sent by the image processor, and calibrate the photosensitive value of each photosensitive element; and the image processor is electrically connected with the plurality of analog-to-digital converters. The photosensitive value of each photosensitive element is calibrated by the electrical signal of the anode of the photosensitive element, and n 2 times of calibrated Bayer images are obtained, which can eliminate the influence of crosstalk and improve the image clarity. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 FIG. 1 is a structural schematic diagram of a pixel circuit provided by the embodiment of the present application;

[0027] Figure 2 FIG. 2 is a first structural schematic diagram of a pixel unit provided by the embodiment of the present application;

[0028] Figure 3 FIG. 3 is a second structural schematic diagram of a pixel unit provided by the embodiment of the present application;

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

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

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

[0032] Figure 7 FIG. 7 is a specific structural schematic diagram of a pixel unit provided by the embodiment of the present application;

[0033] Figure 8 FIG. 8 is a flow schematic diagram of an image generation method according to the embodiment of the present application;

[0034] Figure 9This is a schematic diagram of the hardware structure of an electronic device that implements the embodiments of this application. Detailed Implementation

[0035] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0036] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0037] The pixel circuit, image sensor, camera module, device, and image generation method provided in this application will be described in detail below with reference to the accompanying drawings and through specific embodiments and application scenarios.

[0038] The pixel circuit provided in this application includes multiple rows and columns of pixel units and multiple signal readout units; the input terminals of the multiple signal readout units are electrically connected to each of the multiple rows of pixel units; the multiple signal readout units are electrically connected to each of the multiple 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; the multiple analog-to-digital converters are connected to an image processor; and the image processor generates an image based on the digital signal generated by the analog-to-digital converters.

[0039] like Figure 1 As shown, Figure 1 This is a schematic diagram of the pixel circuit provided in an embodiment of this application. Figure 1 In the image processor 300, the pixel circuit 100 includes multiple rows and columns of pixel units 11 and multiple signal readout units 12; the input terminals of the multiple signal readout units 12 are electrically connected to each of the multiple rows of pixel units 11; the multiple signal readout units 12 are electrically connected to each of the multiple analog-to-digital converters 200; the image processor 300 is electrically connected to the multiple analog-to-digital converters 200; the analog-to-digital converters 200 convert the voltage signals of each row of pixel units sampled into digital signals, and the image processor 300 generates an image based on the digital signals generated by the analog-to-digital converters 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 n rows and n columns of pixel subunits, where n is a positive integer greater than or equal to 2, and the pixel subunits included in the same pixel unit correspond to the same color; a first end of the calibration subunit is electrically connected to a positive electrode of a photosensitive element included in the pixel subunit; a second end of the calibration subunit is electrically connected to a first analog-to-digital converter, where the first analog-to-digital converter is an analog-to-digital converter electrically connected to the row in which the pixel unit is located; a third end of the calibration subunit is electrically connected to an output end of the compensation subunit; an input end of the compensation subunit is electrically connected to an image processor; and the compensation subunit is configured to receive a reference value for calibrating a photosensitive value of each photosensitive element sent by the image processor, and calibrate the photosensitive value of each photosensitive element. The image processor is electrically connected to a plurality of 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 color corresponding to the pixel subunits included in the same pixel unit can be red, can also be red-green, can also be blue-green, and can also be blue.

[0043] As shown in Figure 2 , Figure 2 is a first structure diagram of a pixel unit provided by the embodiments of the present application. In Figure 2 , the pixel unit 11 includes a calibration subunit 112, a compensation subunit 113, and n rows and n columns of pixel subunits 111. A first end of the calibration subunit 112 is electrically connected to a positive electrode of a photosensitive element PD included in the pixel subunit 111; a second end of the calibration subunit 112 is electrically connected to an analog-to-digital converter 200 electrically connected to the row in which the pixel unit 11 is located; a third end of the calibration subunit 112 is electrically connected to an output end of the compensation subunit 113; an input end of the compensation subunit 113 is electrically connected to an image processor 300; and the compensation subunit 113 is configured to receive a reference value for calibrating a photosensitive value of each photosensitive element sent by the image processor 300, and calibrate the photosensitive 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 switch tube, a photosensitive element, and a second switch tube; a negative electrode of the photosensitive element is electrically connected to a source electrode of the first switch tube; a drain electrode of the first switch tube is electrically connected to a first signal readout unit, where the first signal readout unit is a signal readout unit electrically connected to the pixel unit including the photosensitive element; a positive electrode of the photosensitive element is electrically connected to a drain electrode of the second switch tube; and a source electrode of the second switch tube is grounded.

[0045] AsFigure 3 As shown, Figure 3 This is a schematic diagram of a second structure of a pixel unit provided in an embodiment of this application. Figure 3 In the pixel subunit 111, there are a first switch transistor TG1, a photosensitive element PD, and a second switch transistor TG2; the negative terminal of the photosensitive element PD is electrically connected to the source terminal of the first switch transistor TG1; the drain terminal of the first switch transistor TG1 is electrically connected to the signal readout unit 12, which includes the photosensitive element PD; the positive terminal of the photosensitive element PD is electrically connected to the drain terminal of the second switch transistor TG2; and the source terminal of the second switch transistor TG2 is grounded.

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

[0047] like Figure 4 As shown, Figure 4 This is a schematic diagram of the third structure of the pixel unit provided in the embodiments of this application. Figure 4 In the calibration subunit 112, there are a third switch transistor TG3 and a first capacitor C1. The drain of the third switch transistor TG3 is electrically connected to the positive terminal of the photosensitive element PD of the pixel subunit 111; the source of the third switch transistor TG3 is electrically connected to the first plate of the first capacitor C1; the output terminal 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 this application, the calibration subunit may further include: a fourth switching transistor; the drain of the fourth switching transistor is connected to a power supply; and the source of the fourth switching transistor is electrically connected to the first plate of the first capacitor.

[0049] like Figure 5 As shown, Figure 5 This is a schematic diagram of the fourth structure of the pixel unit provided in the embodiments of this application. Figure 5 In the calibration subunit 112, there are a third switch transistor TG3, a first capacitor C1, and a fourth switch transistor TG4. The drain of the third switch transistor TG3 is electrically connected to the positive terminal of the photosensitive element PD of the pixel subunit 111; the source of the third switch transistor TG3 is electrically connected to the first plate of the first capacitor C1, the source of the fourth switch transistor TG4, the output terminal of the compensation subunit 113, and the analog-to-digital converter 200; the drain of the fourth switch transistor is connected to the power supply VDD; and the second plate of the first capacitor C1 is grounded.

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

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

[0052] As shown in Figure 6 , Figure 6 is a fifth structure diagram of a pixel unit provided by the embodiments of the present application. In Figure 6 , the calibration subunit 112 includes a third switch tube TG3, a first capacitor C1, a signal amplifier TG5 and a row selector TG6; a drain of the third switch tube TG3 is electrically connected with an anode of the photosensitive element PD of the pixel subunit 111; a source of the third switch tube TG3 is electrically connected with a first plate of the first capacitor C1, a gate of the signal amplifier TG5 and an output end of the compensation subunit 113 respectively; a second plate of the first capacitor C1 is grounded; a drain of the signal amplifier TG5 is connected with the power supply VDD; a source of the signal amplifier TG5 is electrically connected with a drain of the row selector TG6; and a source of the row selector TG6 is electrically connected with 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 implementation of the embodiments of the present application, the first capacitor in the embodiments of the present application is a variable capacitor.

[0055] Figure 7 is a specific structure diagram of a pixel unit provided by the embodiments of the present application.

[0056] In Figure 7 , the pixel unit 11 includes the calibration subunit 112, the 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; and the signal readout unit 12 includes a reset triode RST, a parasitic capacitor FD, a signal amplifier SF and a row selector SET.

[0057] The 2 rows and 2 columns of pixel subunits include a left-up pixel subunit, a right-up pixel subunit, a left-down pixel subunit and a right-down pixel subunit.

[0058] In some possible implementations in the embodiments of the present application, the switch tube, the signal amplifier, the row selector and the reset triode in the embodiments of the present application can be metal-oxide-semiconductor field-effect transistors (MOSFETs).

[0059] The negative electrode of the photosensitive element PD is electrically connected with the source electrode of the first switch tube TG1; the drain electrode of the first switch tube TG1 is electrically connected with the drain electrode of the reset triode RST, the first plate of the parasitic capacitor FD and the gate electrode of the signal amplifier SF respectively, the second plate of the parasitic capacitor FD is grounded, the source electrode of the reset triode RST and the source electrode of the signal amplifier SF are connected with the power supply VDD, the drain electrode of the signal amplifier SF is electrically connected with the source electrode of the row selector SET; the drain electrode of the row selector SET is electrically connected with the positive electrode of the direct current power supply DC and the analog-to-digital converter 200 respectively; the positive electrode of the photosensitive element PD is electrically connected with the drain electrode of the second switch tube TG2; the source electrode of the second switch tube TG2 is grounded. The analog-to-digital converter 200 is connected with the image processor 300.

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

[0061] When the pixel is exposed, the reset transistor RST, the fourth switch tube TG4 and each pixel subunit including the first switch tube TG1 are opened, and the first capacitor C1 and the parasitic capacitor FD are emptied. The electron-hole pairs generated by light irradiation will separate due to the existence of the electric field of the photosensitive element PD, and the electrons move to the N region and the holes move to the P region. After exposure, the reset transistor RST is closed to reset the parasitic capacitor FD to a high level. After the reset is completed, the parasitic capacitor FD reset level 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. The first switch tube TG1 included in each pixel subunit is closed, and the charge is completely transferred from the photosensitive region to the parasitic capacitor FD for the 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 a voltage signal value B. The two stored voltage signal values are subtracted to obtain a voltage signal corresponding to a pure optical signal. After analog amplification and sampling by the analog-to-digital converter 200, a digital signal corresponding to the optical signal is obtained. The analog-to-digital converter 200 sends the digital signal corresponding to the optical signal of each photosensitive element to the image processor 300, and 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. The digital signal corresponding to the optical signal of each photosensitive element is the photosensitive value of each pixel subunit.

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

[0063] Exemplarily, when the photosensitive value of the photosensitive element included in the upper-left pixel sub-unit is calibrated, the second switch tube TG2 at the positive electrode of the photosensitive element included in the upper-left pixel sub-unit is turned off, the third switch tube TG3 and the fourth switch tube TG4 are turned on, all the positive holes of the photosensitive element included in the upper-left pixel sub-unit are transmitted to the first capacitor C1, and the calibration parameter corresponding to the photosensitive element included in the upper-left pixel sub-unit 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=0.944 uf by the compensation sub-unit. After the capacitance value of the first capacitor C1 becomes 0.944 uf, 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 photosensitive value of the photosensitive element included in the upper-left pixel sub-unit after calibration is 90LSB.

[0064] When the photosensitive value of the photosensitive element included in the upper-right pixel sub-unit is calibrated, the fourth switch tube TG4 is turned off, the first capacitor C1 is emptied, the third switch tube TG3 is turned off, and the second switch tube TG2 at the positive electrode of the photosensitive element included in the upper-left pixel sub-unit is turned on. Then, the second switch tube TG2 at the positive electrode of the photosensitive element included in the upper-right pixel sub-unit is turned off, the third switch tube TG3 and the fourth switch tube TG4 are turned on, and all the positive holes of the photosensitive element included in the upper-right pixel sub-unit are transmitted to the first capacitor C1. The calibration parameter corresponding to the photosensitive element included in the upper-right pixel sub-unit is 90LSB / 110LSB=0.82. Assuming that the original capacitance value of the first capacitor C1 is 1 uf, the capacitance value of the first capacitor C1 is adjusted to 1 / 0.82=1.22 uf by the compensation sub-unit. After the capacitance value of the first capacitor C1 becomes 1.22 uf, 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 through the signal amplifier TG5 and the row selector TG6 for reading, and the photosensitive value of the photosensitive element included in the upper-right pixel sub-unit after calibration is 90LSB.

[0065] When the photosensitive value of the photosensitive element included in the lower left pixel sub-unit is calibrated, the fourth switch tube TG4 is disconnected, the first capacitor C1 is emptied, the third switch tube TG3 is disconnected, the second switch tube TG2 connected to the positive electrode of the photosensitive element included in the upper right pixel sub-unit is closed, then the second switch tube TG2 connected to the positive electrode of the photosensitive element included in the lower right pixel sub-unit is disconnected, 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 sub-unit are all transmitted to the first capacitor C1, and the calibration parameter corresponding to the photosensitive element included in the lower right pixel sub-unit 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 sub-unit. After the capacitance value of the first capacitor C1 is changed to 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 through the signal amplifier TG5 and the row selector TG6 for reading, and the photosensitive value of the photosensitive element included in the lower right pixel sub-unit after calibration is 90LSB.

[0066] When the photosensitive value of the photosensitive element included in the lower left pixel sub-unit is calibrated, the fourth switch tube TG4 is disconnected, the first capacitor C1 is emptied, the third switch tube TG3 is disconnected, the second switch tube TG2 connected to the positive electrode of the photosensitive element included in the upper right pixel sub-unit is closed, then the second switch tube TG2 connected to the positive electrode of the photosensitive element included in the lower right pixel sub-unit is disconnected, 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 sub-unit are all transmitted to the first capacitor C1, and the calibration parameter corresponding to the photosensitive element included in the lower right pixel sub-unit 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 sub-unit. After the capacitance value of the first capacitor C1 is changed to 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 through the signal amplifier TG5 and the row selector TG6 for reading, and the photosensitive value of the photosensitive element included in the lower right pixel sub-unit after calibration is 90LSB.

[0067] In the embodiment of the present application, the photosensitive value of each pixel sub-unit is calibrated through the electrical signal of the positive electrode of the photosensitive element, the influence of crosstalk can be eliminated, and then when the multiple Bayer image is processed into a Bayer image by using the remosaic algorithm, the image definition can be improved.

[0068] The positive electrode and the negative electrode of the pixel subunit in the embodiment of the present application can output two kinds of voltage signals, while not affecting the normal pixel function, the high-resolution image after the calibration crosstalk can also be obtained, the number of real light pixels can be effectively improved, the image blur caused by the movement of the user when taking a picture or the movement of the scene can not occur, and the image quality can be improved.

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

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

[0071] The embodiment of the present application also provides an electronic device comprising the camera module provided by the embodiment of the present application.

[0072] The electronic device in the embodiment of the present application can be a terminal or other devices except the terminal. For example, the electronic device can be a mobile phone, a tablet computer, a notebook computer, a palm computer, 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. The electronic device can 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. The embodiment of the present application is not limited specifically.

[0073] The electronic device in the embodiment of the present application can be an electronic device with an operating system. The operating system can be an Android operating system, an iOS operating system, or other possible operating systems. The embodiment of the present application is not limited specifically.

[0074] The embodiment of the present application also provides an image generation method applied to the electronic device provided by the embodiment of the present application.

[0075] Figure 8 FIG. 1 is a flowchart of the image generation method provided by the embodiment of the present application. The image generation method can include the following steps:

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

[0077] Step 802: determining a reference value for calibrating the photosensitive value of the pixel sub-unit according to the photosensitive value;

[0078] Step 803: calibrating the photosensitive value of each pixel sub-unit according to the reference value to obtain n rows and n columns of calibrated pixel sub-units. 2

[0079] In some possible implementations of the embodiments of the present application, step 802 can include: determining an average value of the photosensitive value of the pixel sub-unit in n rows and n columns of pixel sub-units; and taking the average value as the reference value corresponding to n rows and n columns of pixel sub-units.

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

[0081] For example, the following takes 2 rows and 2 columns of pixel sub-units including a left upper pixel sub-unit, a right upper pixel sub-unit, a left lower pixel sub-unit and a right lower pixel sub-unit as an example for illustration. Assuming that the photosensitive value of the photosensitive element included in the left upper pixel sub-unit is 85 least significant bits (LSB), the photosensitive value of the photosensitive element included in the right upper pixel sub-unit is 110 LSB, the photosensitive value of the photosensitive element included in the left lower pixel sub-unit is 90 LSB, and the photosensitive value of the photosensitive element included in the right lower pixel sub-unit is 75 LSB, the reference value for calibrating the photosensitive value of the photosensitive element included in the pixel sub-unit is (85+110+90+75) / 4=90 LSB. Then the photosensitive value of the photosensitive element included in the pixel sub-unit is calibrated to 90 LSB.

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

[0083] ​Exemplarily, the following takes the left upper pixel subunit, the right upper pixel subunit, the left lower pixel subunit and the right lower pixel subunit as examples for illustration. The photosensitive value of the photosensitive element included in the left upper pixel subunit is 85 LSB, the photosensitive value of the photosensitive element included in the right upper pixel subunit is 110 LSB, the photosensitive value of the photosensitive element included in the left lower pixel subunit is 90 LSB, and the photosensitive value of the photosensitive element included in the right lower pixel subunit is 75 LSB. The reference value corresponding to the 2-row 2-column pixel subunit is (85+110+90+75) / 4=90 LSB.

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

[0085] When the photosensitive value of the photosensitive element included in the left upper pixel subunit is calibrated, the second switch tube at the positive electrode end of the photosensitive element included in the left upper pixel subunit is disconnected, the third switch tube and the fourth switch tube are closed, all the positively charged holes of the photosensitive element included in the left upper pixel subunit are transmitted to the first capacitor, and the calibration parameter corresponding to the photosensitive element included in the left upper pixel subunit is 90 LSB / 85 LSB=1.059. Assuming that the original capacitance value of the first capacitor is 1 uf, the capacitance value of the first capacitor is adjusted to 1 / 1.059=0.944 uf through the compensation subunit. After the capacitance value of the first capacitor becomes 0.944 uf, 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 for reading through the signal amplifier and the row selector, and the calibrated photosensitive value of the photosensitive element included in the left upper pixel subunit is 90 LSB.

[0086] When the photosensitive value of the photosensitive element included in the left lower pixel sub-unit is calibrated, the fourth switch tube is disconnected, the first capacitor is emptied, the third switch tube is disconnected, the second switch tube of the anode end of the photosensitive element included in the right upper pixel sub-unit is closed, then the second switch tube of the anode end of the photosensitive element included in the left lower pixel sub-unit is disconnected, the third switch tube and the fourth switch tube are closed, all the positively charged holes of the photosensitive element included in the left lower pixel sub-unit are transmitted to the first capacitor, and the calibration parameter corresponding to the photosensitive element included in the left lower pixel sub-unit 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 sub-unit. 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 for reading through the signal amplifier and the row selector, and the photosensitive value of the photosensitive element included in the left lower pixel sub-unit after calibration is 90LSB.

[0087] When the photosensitive value of the photosensitive element included in the right lower pixel sub-unit is calibrated, the fourth switch tube is disconnected, the first capacitor is emptied, the third switch tube is disconnected, the second switch tube of the anode end of the photosensitive element included in the left lower pixel sub-unit is closed, then the second switch tube of the anode end of the photosensitive element included in the right lower pixel sub-unit is disconnected, the third switch tube and the fourth switch tube are closed, all the positively charged holes of the photosensitive element included in the right lower pixel sub-unit are transmitted to the first capacitor, and the calibration parameter corresponding to the photosensitive element included in the right lower pixel sub-unit 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 sub-unit. 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 for reading through the signal amplifier and the row selector, and the photosensitive value of the photosensitive element included in the right lower pixel sub-unit after calibration is 90LSB.

[0088] In the embodiment of the present application, the photosensitive value of each pixel sub-unit is calibrated through the electrical signal of the anode end of the photosensitive element, the influence of crosstalk can be eliminated, and then when the multiple Bayer image is processed into a Bayer image by using the remosaic algorithm, the image definition can be improved.

[0089] Figure 9 is a schematic diagram of the hardware structure of an electronic device for implementing the 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 the like.

[0091] Those skilled in the art can understand that the electronic device 900 can further include a power supply (such as a battery) for supplying power to each component, and the power supply can be logically connected to the processor 910 through a power management system, so as to realize the functions of managing charging, discharging, and power consumption management through the power management system. Figure 9 The electronic device structure shown in the figure does not constitute a limitation on the electronic device, and the electronic device can include more or fewer components than the figure, or combine certain components, or different component arrangements, which are not described here.

[0092] Among them, the electronic device 900 in the embodiment of the application includes the camera module provided by the embodiment of the application, the camera module provided by the embodiment of the application includes the image sensor provided by the embodiment of the application, and the image sensor provided by the embodiment of the application includes the pixel circuit provided by the embodiment of the application.

[0093] The processor 910 is configured to: acquire a photosensitive value of each pixel subunit in n rows and n columns of pixel subunits; determine a reference value for calibrating the photosensitive value of the pixel subunit according to the photosensitive value; and calibrate the photosensitive value of each pixel subunit according to the reference value to obtain a calibrated n2 times Bayer image.

[0094] In the embodiment of the application, by calibrating the photosensitive value of each pixel subunit, the influence of crosstalk can be eliminated, and then when the multiple Bayer image is processed into a Bayer image by using a remosaic algorithm, the image definition can be improved.

[0095] It should be understood that in the embodiments of the present application, the input unit 904 can include a graphics processing unit (GPU) 9041 and a microphone 9042. The graphics processing unit 9041 processes image data of a still picture or a video obtained by an image capture device (such as a camera) in a video capture mode or an image capture mode. The display unit 906 can include a display panel 9061, which can be configured in the form of a liquid crystal display, an organic light-emitting diode, etc. The user input unit 907 includes at least one of a touch panel 9071 and other input devices 9072. The touch panel 9071 is also referred to as a touch screen. The touch panel 9071 can include two parts of a touch detection device and a touch controller. The other input devices 9072 can include, but are not limited to, a physical keyboard, function keys (such as volume control keys, on-off keys, etc.), a trackball, a mouse, a joystick, and the like, which will not be described here.

[0096] The memory 909 can be used to store software programs and various data. The memory 909 can mainly include a first storage area storing programs or instructions and a second storage area storing data, wherein the first storage area can store an operating system, application programs or instructions required by at least one function (such as a sound playing function, an image playing function, etc.), and the like. In addition, the memory 909 can include a volatile memory or a non-volatile memory, or the memory 909 can include both volatile and non-volatile memories. The non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically EPROM (EEPROM), or a flash memory. The volatile memory can 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 (DDR SDRAM), an enhanced synchronous dynamic random access memory (ESDRAM), a synch link DRAM (SLDRAM), and a direct memory bus random access memory (Direct Rambus RAM, DRRAM). The memory 909 in the embodiments of the present application includes but is not limited to these and any other suitable types of memory.

[0097] The processor 910 can 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 operating systems, user interfaces, and application programs, and the modem processor mainly processes wireless communication signals, such as a baseband processor. It can be understood that the above-mentioned modem processor can also not be integrated into the processor 910.

[0098] The embodiment of the present application further provides a readable storage medium, and the readable storage medium stores a program or instructions, the program or instructions are executed by a processor to realize various processes of the above-mentioned image generation method embodiment, and the same technical effects can be achieved, to avoid repetition, which will not be repeated here.

[0099] The processor is the processor in the electronic device in the above-mentioned embodiment. The readable storage medium includes a computer readable storage medium, and examples of the computer readable storage medium include non-transitory computer readable media, such as a computer readable only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and the like.

[0100] The embodiment of the present application further provides a chip, and the chip includes a processor and a communication interface, the communication interface is coupled with the processor, and the processor is used to run a program or instructions to realize various processes of the above-mentioned image generation method embodiment, and the same technical effects can be achieved, to avoid repetition, which will not be repeated here.

[0101] It should be understood that the chip mentioned in the embodiment of the present application can also be referred to as a system level chip, a system chip, a chip system, or a system on chip, etc.

[0102] The embodiment of the present application further provides a computer program product, and the program product is stored in a storage medium, and the program product is executed by at least one processor to realize various processes of the above-mentioned image generation method embodiment, and the same technical effects can be achieved, to avoid repetition, which will not be repeated here.

[0103] It should be noted that, in the present document, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises... a" does not, without more constraints, exclude the presence of additional identical elements in the process, method, article, or apparatus that comprises the element. Furthermore, it is to be understood that the method and apparatus of the present application can be carried out by more than one process, method, article, or apparatus either simultaneously, concurrently, or with intervening action that are carried out at the same time, either in a simultaneous fashion or in a fashion that is interleaved in time. For example, the described methods can be performed in a different order from that described, and / or various steps can be combined or omitted, and / or additional steps can be added, without departing from the scope of the present application. Also, features described with respect to certain examples can be combined in other examples.

[0104] From the above description of the embodiments, it is apparent that the above-mentioned method can be realized by means of software and necessary universal hardware platform, of course, it can also be realized by hardware, but in many cases, the former is a better embodiment. Based on such understanding, the technical solution of the present application can be embodied in the form of computer software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a plurality of instructions for making a terminal (which can be a mobile phone, computer, server, or network equipment, etc.) execute the method described in various embodiments 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-described specific embodiments, and the above-described specific embodiments are merely illustrative, rather than limiting, and those skilled in the art can make many forms under the inspiration of the present application without departing from the scope of the present application and the scope protected by the claims.

Claims

1. A pixel circuit, characterized by comprising: The pixel circuit comprises a plurality of rows and columns of pixel units and a plurality of signal readout units; The input end of the plurality of signal readout units is electrically connected to the plurality of rows of pixel units one by one; The output end of the plurality of signal readout units is electrically connected to a plurality of analog-to-digital converters one by one; 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 comprises a calibration subunit, a compensation 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 correspond to 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 in which the pixel unit is located; The third end of the calibration subunit is electrically connected to the output end of the compensation subunit; The input end of the compensation subunit is electrically connected to an image processor; the compensation subunit is used to receive the reference value sent by the image processor for calibrating the photosensitive value of each photosensitive element, and calibrate the photosensitive value of each photosensitive element; The image processor is electrically connected to the plurality of analog-to-digital converters.

2. The pixel circuit of claim 1, wherein, The pixel subunit comprises a first switch tube, a photosensitive element and a second switch tube; The negative electrode of the photosensitive element is electrically connected to the source electrode of the first switch tube; The drain electrode 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 the 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 electrode of the second switch tube is grounded.

3. The pixel circuit of claim 1, wherein, The calibration subunit comprises a third switch tube and a first capacitor; The drain electrode of the third switch tube is electrically connected to the positive electrode of the photosensitive element of the pixel subunit; The source electrode 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 of claim 3, wherein, The calibration subunit further comprises a fourth switch tube; The drain electrode of the fourth switch tube is connected to a power supply; The source electrode of the fourth switch tube is electrically connected to the first plate of the first capacitor.

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

6. The pixel circuit of claim 3, wherein, The first capacitor is a variable capacitor.

7. An image sensor, characterized by The image sensor comprises the pixel circuit of any one of claims 1 to 6.

8. An image capture module, comprising: The camera module comprises the image sensor of claim 7.

9. An electronic device, comprising: The electronic device comprises the camera module of claim 8.

10. An image generation method characterized by, The method is applied to the electronic device of claim 9; the method comprises: Obtaining the photosensitive value of each pixel subunit in the n rows and n columns of pixel subunits; According to the light-sensing value, a reference value for calibrating the light-sensing value of the pixel sub-unit is determined; According to the reference value, the photosensitive value of each pixel sub-unit is calibrated, and n 2 times of the calibrated Bayer image is obtained.

11. The method of claim 10, wherein, The method according to the light-sensing value, the reference value for calibrating the light-sensing value of the pixel sub-unit comprises: Determining the average value of the light-sensing value of the pixel sub-unit in the n rows and n columns of pixel sub-units; The average value is taken as the reference value corresponding to the n rows and n columns of pixel sub-units.

12. The method of claim 10, wherein, The method according to the reference value for calibrating the light-sensing value of each pixel sub-unit comprises: Calibrating the light-sensing value of each pixel sub-unit to the reference value.

13. The method of claim 12, wherein, The method of calibrating the light-sensing value of each pixel sub-unit to the reference value comprises: For a first pixel sub-unit, calculating the ratio of the reference value to the light-sensing value of the first pixel sub-unit, wherein the first pixel sub-unit is any one of the n rows and n columns of pixel sub-units; Disconnecting the second switch tube electrically connected between the first pixel sub-unit and the positive electrode of the light-sensing element; Closing the third switch tube included in the calibration sub-unit; Adjusting the capacitance value of the first capacitor included in the calibration sub-unit to one divided by the ratio of the original capacitance value of the first capacitor through the compensation sub-unit, so as to calibrate the light-sensing value of the first pixel sub-unit to the reference value.

Images