WO2023035902A1

WO2023035902A1 - Image sensor, camera assembly, and mobile terminal

Info

Publication number: WO2023035902A1
Application number: PCT/CN2022/113487
Authority: WO
Inventors: 杨鑫
Original assignee: Oppo广东移动通信有限公司
Priority date: 2021-09-09
Filing date: 2022-08-19
Publication date: 2023-03-16
Also published as: CN113747022B; CN113747022A

Abstract

The present application relates to an image sensor (10). The image sensor (10) comprises: a pixel array (11) comprising a plurality of subunits (111), each subunit (111) comprising two pixel circuits, wherein one pixel circuit comprises a plurality of first photoelectric conversion elements (1111), the other pixel circuit comprises a plurality of second photoelectric conversion elements (1111'), and the pixel circuits are used for transferring a charge generated by the at least one first photoelectric conversion element (1111) or the at least one second photoelectric conversion element (1111') to a corresponding floating diffusion region for accumulation, and outputting an analog signal corresponding to the accumulated charge in the floating diffusion region; and a plurality of conversion circuits (141), each conversion circuit (141) comprising two analog-to-digital converters which are respectively connected to the two pixel circuits, and the conversion circuits (141) being used for reading, on the basis of a full-resolution output mode or a combined output mode together with at least one of the two pixel circuits, a digital signal converted from analog signal.

Description

Image sensors, camera components and mobile terminals

Cross References to Related Applications

This application claims the priority of the Chinese patent application with the application number 2021110557628 and the title of the invention "image sensor, camera assembly and mobile terminal" filed with the China Patent Office on September 09, 2021, the entire contents of which are incorporated by reference in this application middle.

technical field

The present application relates to the field of image technology, in particular to an image sensor, a camera assembly and a mobile terminal.

Background technique

The statements herein merely provide background information related to the present application and do not necessarily constitute prior art.

A camera may be installed in a terminal such as a mobile phone to realize a camera function. An image sensor for receiving light may be arranged in the camera.

As demand for image sensors increases, techniques for improving the quality of images generated by the image sensors are being developed. It is difficult for general image sensors to balance the imaging quality in high-brightness scenes and low-light scenes.

Contents of the invention

According to various embodiments of the present application, an image sensor, a camera assembly, and a mobile terminal are provided.

An image sensor comprising:

A pixel array comprising a plurality of subunits, each of the subunits comprising a plurality of color pixels and a plurality of panchromatic pixels, wherein the color pixels have a narrower spectral response than the panchromatic pixels; wherein the subunits The unit includes two pixel circuits, wherein one of the pixel circuits includes a plurality of first photoelectric conversion elements corresponding to a plurality of color pixels, and the other pixel circuit includes a plurality of first photoelectric conversion elements corresponding to a plurality of panchromatic pixels. A plurality of second photoelectric conversion elements are provided, wherein the pixel circuit is used to transfer the charge generated by at least one first photoelectric conversion element or at least one second photoelectric conversion element corresponding to the pixel of the same color in the subunit to the corresponding accumulate in the floating diffusion area, and output an analog signal corresponding to the accumulated charge in the floating diffusion area; and

A plurality of conversion circuits are respectively connected to a plurality of the subunits in one-to-one correspondence, wherein the conversion circuits include two analog-to-digital converters respectively connected to the two pixel circuits in a one-to-one correspondence, and the conversion circuits are used to communicate with At least one of the two pixel circuits jointly reads out the digital signal converted from the analog signal based on a full-resolution output mode or a combined output mode, wherein the full-resolution output mode is used for readout in units of pixels For the digital signal, the combined output mode is used to read out the digital signal in units of at least two pixels with the same color in the subunit.

A camera assembly, comprising:

lens; and

In the aforementioned image sensor, the image sensor is capable of receiving light passing through the lens.

A mobile terminal, comprising:

casing; and

In the foregoing camera assembly, the camera assembly is combined with the housing.

The above image sensor, camera assembly and mobile terminal, the image sensor includes a pixel array and multiple conversion circuits. Wherein, the pixel array includes a plurality of subunits, and each of the subunits includes a plurality of color pixels and a plurality of panchromatic pixels, wherein the subunits include two pixel circuits, and one of the pixel circuits includes multiple a plurality of first photoelectric conversion elements arranged in one-to-one correspondence with color pixels, and the other pixel circuit includes a plurality of second photoelectric conversion elements arranged in one-to-one correspondence with a plurality of panchromatic pixels, wherein the pixel circuit uses Transferring the charge generated by at least one first photoelectric conversion element or at least one second photoelectric conversion element corresponding to the same color pixel in the sub-unit to the corresponding floating diffusion area for accumulation, and outputting the accumulated charge in the floating diffusion area Corresponding to the analog signal, each of the conversion circuits includes two analog-to-digital converters respectively connected to the two pixel circuits in one-to-one correspondence, and the conversion circuit is used to work with at least one of the two pixel circuits based on the full The resolution output mode or the combined output mode reads out the digital signal converted from the analog signal. That is to say, the image sensor provided in the present application can provide multiple output modes applicable to different imaging scenarios, and can have good imaging quality in different scenarios. Exemplarily, when imaging in dark light, the combined output mode can be used to achieve combined output in units of at least two pixels with the same color in the subunit, so as to obtain an image with a high signal-to-noise ratio, while in a scene with sufficient light In this case, the full-resolution output mode can be used to realize individual output in units of pixels, so as to obtain images with high definition and signal-to-noise ratio.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present application. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

FIG. 1 is a schematic diagram of an image sensor in an embodiment;

Fig. 2 is a schematic diagram of arrangement of a pixel array in an embodiment;

FIG. 3 is a schematic diagram of a three-dimensional structure of an image sensor in an embodiment;

FIG. 4 is one of the schematic circuit diagrams of two pixel circuits of a subunit in an embodiment;

Fig. 5 is a schematic diagram of the arrangement of subunits in an embodiment;

FIG. 6 is the second schematic circuit diagram of two pixel circuits of a subunit in an embodiment;

FIG. 7 is the third schematic circuit diagram of two pixel circuits of a subunit in an embodiment;

FIG. 8 is a fourth schematic circuit diagram of two pixel circuits of a subunit in an embodiment;

FIG. 9 is a schematic diagram of conversion of a subunit based on a full-resolution output mode in an embodiment;

FIG. 10 is a schematic diagram of conversion of subunits based on the first-stage combined output mode in an embodiment;

FIG. 11 is a schematic diagram of conversion of subunits based on the second-level combined output mode in an embodiment;

Fig. 12 is a fifth schematic circuit diagram of two pixel circuits of a subunit in an embodiment;

Fig. 13 is a sixth schematic circuit diagram of two pixel circuits of a subunit in an embodiment;

Fig. 14 is the seventh schematic circuit diagram of two pixel circuits of a subunit in an embodiment;

Fig. 15 is an eighth schematic circuit diagram of two pixel circuits of a subunit in an embodiment;

Figure 16 is a schematic diagram of a camera assembly in one embodiment;

Figure 17 is a schematic diagram of a mobile terminal in one embodiment.

Detailed ways

In order to make the purpose, technical solution and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present application, and are not intended to limit the present application.

It can be understood that the terms "first", "second" and the like used in this application may be used to describe various elements herein, but these elements are not limited by these terms. These terms are only used to distinguish one element from another element. For example, a first switching unit could be termed a second switching unit, and, similarly, a second switching unit could be termed a first switching unit, without departing from the scope of the present application. Both the first switching unit and the second switching unit are switching units, but they are not the same switching unit.

As shown in FIG. 1 , an embodiment of the present application provides an image sensor. The image sensor 10 includes a pixel array 11 , a vertical driving unit 12 , a control unit 13 , a column processing unit 14 and a horizontal driving unit 15 .

Wherein, the image sensor 10 may adopt a complementary metal oxide semiconductor (CMOS, Complementary Metal Oxide Semiconductor) photosensitive element or a charge-coupled device (CCD, Charge-coupled Device) photosensitive element.

As shown in FIG. 2 , the pixel array 11 includes a plurality of color pixels (eg, A, B, C) and a plurality of panchromatic pixels W arranged two-dimensionally in an array (ie, arranged in a two-dimensional matrix). Among other things, color pixels have a narrower spectral response than panchromatic pixels. Specifically, the color pixel may include one of a first color pixel A, a second color pixel B, and a third color pixel C. Exemplarily, the first color pixel A may be a red pixel R; the second color pixel B may be a green pixel G; and the third color pixel C may be a blue pixel Bu. The response spectrum of a color pixel is, for example, part of the W response spectrum of a panchromatic pixel.

The two-dimensional pixel array 11 includes a plurality of minimum repeating units 110 . The smallest repeating unit 110 is replicated and arranged in rows and columns. Exemplarily, the pixel array 11 includes, but not limited to, 4 rows and 4 columns, 6 rows and 6 columns, 8 rows and 8 columns, and 10 rows and 10 columns of minimum repeating units 110 . Each minimal repeating unit 110 includes a plurality of subunits 111 . Each minimal repeating unit 110 includes, but is not limited to, 2 rows and 2 columns, 3 rows and 3 columns, and 4 rows and 4 columns subunits 111 . Exemplarily, each minimum repeating unit 110 may include four subunits 111, wherein one subunit 111 includes a plurality of first color pixels A and a plurality of panchromatic pixels W, and two subunits 111 include a plurality of second color pixels B and a plurality of panchromatic pixels W, and the remaining subunit 111 includes a plurality of third color pixels C and a plurality of panchromatic pixels W. Each subunit 111 includes a plurality of color pixels and a plurality of panchromatic pixels W. In the same subunit 111, the colors of the multiple color pixels are the same, that is, the multiple color pixels are all single-color pixels.

Specifically, the smallest repeating unit can be 8 rows and 8 columns of 64 pixels, and the arrangement is as follows:

Wherein, W represents a panchromatic pixel; A represents a first color pixel among the plurality of color pixels; B represents a second color pixel among the plurality of color pixels; C represents a third color pixel among the plurality of color pixels. The panchromatic pixels W are arranged in the first diagonal direction D1, and the color pixels are arranged in the second diagonal direction D2.

Specifically, the subunit 111 includes m rows and m columns of pixels. Wherein, m is a positive integer greater than or equal to 2. Specifically, m can be 2, 3, 4, 5, 6, 8, 10, etc. Specifically, in the subunit 111, the panchromatic pixels W are arranged in the first diagonal direction D1, and the color pixels are arranged in the second diagonal direction D2. Meanwhile, in the minimum repeating unit 110 , the panchromatic pixels W are arranged in the first diagonal direction D1 , and the color pixels are arranged in the second diagonal direction D2 . The first diagonal direction D1 is different from the second diagonal direction D2. For example, the first diagonal and the second diagonal are perpendicular.

Optionally, the color pixels W may also be arranged in the first diagonal direction D1, and the panchromatic pixels W may be arranged in the second diagonal direction D2.

It should be noted that the first diagonal direction D1 and the second diagonal direction D2 are not limited to diagonals, but also include directions parallel to the diagonals. The "direction" here is not a single pointing, but can be understood as the concept of a "straight line" indicating the arrangement, and there can be two-way pointing at both ends of the line.

The arrangement of diagonal dots and lines provided by the embodiment of the present application can help to balance the resolution and color performance of images in the row and column directions, and improve the display effect.

Please continue to refer to FIG. 1 and FIG. 2 , the vertical driving unit 12 includes a shift register and an address decoder. The vertical drive unit 12 includes readout scanning and reset scanning functions. The readout scan refers to sequentially scanning the unit subcells 111 row by row, and reading signals from the unit subcells 111 row by row. For example, the signal output by each subunit 111 in the selected and scanned subunit row is transmitted to the column processing unit 14 . The reset scan is for resetting the charge, and the photocharge of the photoelectric conversion element is discarded so that accumulation of new photocharge can be started.

For example, the signal processing performed by the column processing unit 14 is correlated double sampling (CDS) processing. In the CDS process, the reset level and signal level output from each subunit 111 in the selected subunit row are taken out, and the level difference is calculated. Thus, the signals of the subunits 111 in one row are obtained. The column processing unit 14 may have an analog-to-digital (A/D) conversion function for converting an analog pixel signal into a digital format, and a function of performing an averaging operation on a plurality of digital signals after the analog-to-digital conversion.

For example, the horizontal driving unit 15 includes a shift register and an address decoder. The horizontal driving unit 15 sequentially scans the pixel array 11 column by column. Each sub-unit column is sequentially processed by the column processing unit 14 through the selection scanning operation performed by the horizontal driving unit 15, and is sequentially output.

For example, the control unit 13 configures timing signals according to the operation mode, and uses various timing signals to control the vertical driving unit 12 , the column processing unit 14 and the horizontal driving unit 15 to work together. At the same time, the control unit can also control the on or off state of each switch unit in the image sensor.

As shown in FIG. 3 , the image sensor also includes a filter array 16 and a microlens array 17 . The filter array 16 includes a plurality of filters 161, and each filter 161 covers a corresponding pixel. The spectral response of each pixel (that is, the color of light that the pixel can receive) is determined by the color of the filter 161 corresponding to the pixel. Color pixels and panchromatic pixels are distinguished by the wavelength bands of light that can pass through the filter 161 covered thereon. The microlens array 17 includes a plurality of lenses 171 , and each lens 171 covers a corresponding subunit 111 , or each lens 171 may also cover a corresponding pixel.

As shown in Figure 4, each sub-unit includes two pixel circuits, wherein one pixel circuit includes a plurality of first photoelectric conversion elements 1111 corresponding to a plurality of color pixels, and the other pixel circuit includes a plurality of full-color pixels. A plurality of second photoelectric conversion elements 1111' are arranged in one-to-one correspondence with the pixels. Wherein, the photoelectric conversion element may be a photodiode (Photodiode, PD), further, the photoelectric conversion element may be a clamped photodiode (Pinned Photodiode, PPD). The photoelectric conversion element serves to convert light into charges according to the intensity of light incident thereon. The number and arrangement of the first photoelectric conversion elements 1111 are the same as the number and arrangement of the color pixels. The number and arrangement of the second photoelectric conversion elements 1111' are the same as the number and arrangement of the panchromatic pixels.

The pixel circuit is used to convert the received optical signal into an electrical signal, and provide the generated electrical signal to the column processing unit 14 shown in FIG. 1 . Wherein, the pixel circuits each include a floating diffusion area, wherein pixels of the same color can share the floating diffusion area of the pixel circuit. That is, all color pixels in a subunit can share one floating diffusion; all panchromatic pixels in a subunit can share another floating diffusion.

It should be noted that, in the embodiment of the present application, the photoelectric conversion element corresponding to the full-color pixel can also be referred to as the first photoelectric conversion element 1111, and the photoelectric conversion element corresponding to the color pixel can be referred to as the second photoelectric conversion element 1111. Conversion element 1111'. For the convenience of description, in the embodiment of the present application, the photoelectric conversion elements arranged corresponding to the panchromatic pixels are called the second photoelectric conversion elements 1111', and the photoelectric conversion elements arranged corresponding to the color pixels are called the first photoelectric conversion elements. Component 1111 will be described as an example.

The two pixel circuits may include a first pixel circuit 101 and a second pixel circuit 102 . Wherein, the first pixel circuit 101 may include a first floating diffusion region FD1 , and all color pixels in the same subunit 111 share the first floating diffusion region FD1 . Specifically, the first pixel circuit 101 is configured to transfer the first charge generated by the first photoelectric conversion element 1111 corresponding to at least one color pixel in the same subunit 111 to the first floating diffusion region FD1 for accumulation, and output the first floating charge A first analog signal corresponding to the first charges in the diffusion region FD1. The second pixel circuit 102 includes a second floating diffusion region FD2, and all the panchromatic pixels in the same subunit 111 share the second floating diffusion region FD2. That is, the second pixel circuit 102 can transfer the second charge generated by the second photoelectric conversion element 1111' corresponding to at least one full-color pixel to the second floating diffusion region FD2 for accumulation, and output the second charge in the second floating diffusion region FD2. The second analog signal corresponding to the two charges.

Please continue to refer to FIG. 4 , the image sensor further includes a plurality of conversion circuits 141 . Wherein the conversion circuit 141 can be integrated in the column processing unit 14 . A plurality of conversion circuits 141 may be respectively connected to a plurality of subunits 111 in a one-to-one correspondence. The conversion circuit 141 includes two analog-to-digital converters respectively connected to the two pixel circuits in a one-to-one correspondence. The analog-to-digital converter converts the analog signal output from the pixel circuit into a digital signal. Further, the conversion circuit 141 can also work with at least one of the two pixel circuits to read out the digital signal converted from the analog signal based on the full-resolution output mode or the combined output mode.

In the embodiment of the present application, for the convenience of description, the two analog-to-digital converters in the conversion circuit 141 may include a first analog-to-digital converter 1411 and a second analog-to-digital converter 1412 . Wherein, the plurality of first analog-to-digital converters 1411 are respectively connected to the plurality of first pixel circuits 101 in one-to-one correspondence, and the first analog-to-digital converters 1411 are used to convert the first analog signal output by the first pixel circuit 101 into a first For digital signals, the second analog-to-digital converter 1412 is used to convert the second analog signal output by the second pixel circuit 102 into a second digital signal. The conversion circuit 141 can work with at least one of the first pixel circuit 101 and the second pixel circuit 102 to read out the converted digital signals of the first analog signal and the second analog signal based on the full resolution output mode or the combined output mode.

Among them, the full-resolution output mode is used to read out digital signals in units of pixels. The binning output mode is used to read out digital signals in units of at least two pixels having the same color in a subunit. In the combined output mode, at least two color pixels with the same color in the subunit are used as the first unit and at least two full-color pixels in the subunit are used as the second unit to read digital signals. In the embodiment of the present application, the combined output mode can be divided into a first-level combined output mode and a second-level combined output mode, wherein the first-level combined output mode can be understood as: the subunit 111 partially has the same color A digital signal is read out in units of pixels. The second-level combined output mode can be understood as: reading out digital signals in units of all pixels with the same color in the subunit 111 .

The image sensor in the embodiment of the present application includes a pixel array and a plurality of conversion circuits. Wherein, the pixel array includes a plurality of sub-units, and each sub-unit includes a plurality of color pixels and a plurality of panchromatic pixels, wherein the sub-unit includes two pixel circuits, wherein one pixel circuit includes a plurality of color pixels corresponding to each other. A plurality of first photoelectric conversion elements are provided, and another pixel circuit includes a plurality of second photoelectric conversion elements corresponding to a plurality of full-color pixels one by one, wherein the pixel circuit is used for at least Charges generated by one first photoelectric conversion element or at least one second photoelectric conversion element are transferred to the corresponding floating diffusion area for accumulation, and an analog signal corresponding to the accumulated charge in the floating diffusion area is output, and each conversion circuit includes two pixels respectively The two analog-to-digital converters are connected one by one, and the conversion circuit is used to read out the digital signal converted from the analog signal together with at least one of the two pixel circuits based on the full-resolution output mode or the combined output mode. That is to say, the image sensor provided in the present application can provide multiple output modes, can be applied to different imaging scenarios, and can have good imaging quality in different scenarios. Exemplarily, when imaging in dark light, the combined output mode can be used to achieve combined output in units of at least two pixels with the same color in the subunit, so as to obtain an image with a high signal-to-noise ratio, while in a scene with sufficient light In this case, the full-resolution output mode can be used to realize individual output in units of pixels, so as to obtain images with high definition and signal-to-noise ratio.

Please continue to refer to FIG. 4 , the first pixel circuit 101 and the second pixel circuit 102 in FIG. 4 can be applied in each subunit 111 in the pixel array 11 shown in FIG. 2 . The working principle of the pixel circuit will be described below with reference to FIG. 2 to FIG. 4 .

The pixel circuit can transfer the charge generated by at least one first photoelectric conversion element 1111 or at least one second photoelectric conversion element 1111' corresponding to the same color pixel in the same subunit 111 to the corresponding floating diffusion area for accumulation, and output the charge in the floating diffusion area The analog signal corresponding to the accumulated charge in . Wherein, each pixel circuit may further include a plurality of transfer transistors and a readout circuit. That is, all color pixels in a subunit can share one floating diffusion region and one readout circuit; all panchromatic pixels W in a subunit can share another floating diffusion region and another readout circuit.

For ease of description, the transfer transistor included in the first pixel circuit 101 may be referred to as a first transfer transistor 1112 , and the readout circuit included in the first pixel circuit 101 may be referred to as a first readout circuit 1113 . The transfer transistor included in the second pixel circuit 102 may be referred to as a second transfer transistor 1112', and the readout circuit included in the second pixel circuit 102 may be referred to as a second readout circuit 1113'.

Wherein, the number of the first transfer transistors 1112 is equal to the number of the first photoelectric conversion elements 1111 . The first terminals of the multiple first transfer transistors 1112 are respectively connected to the cathodes of the multiple first photoelectric conversion elements 1111 in one-to-one correspondence, and the anodes of the first photodiodes can be connected to the ground. The second end of each first transfer transistor 1112 is connected to the first floating diffusion region FD1. The control terminal of the first transfer transistor 1112 is used to receive a transfer control signal, and is used to transfer the charge generated by the correspondingly connected first photoelectric conversion element 1111 to the first floating diffusion region FD1 under the control of the transfer control signal. In the embodiment of the present application, by controlling multiple first transfer transistors 1112 at the same time, the charges generated by multiple first photoelectric conversion elements 1111 correspondingly connected to them can be transferred to the first floating diffusion region FD1 at the same time or in time division. .

Correspondingly, the second end of each second transfer transistor 1112' is connected to the second floating diffusion region FD2. The plurality of second transfer transistors 1112' can simultaneously or time-divisionally transfer the charges generated by the correspondingly connected second photoelectric conversion elements 1111' to the second floating diffusion region FD2. In the embodiment of the present application, the working principle of the second transfer transistor 1112' is the same as that of the first transfer transistor 1112, and will not be repeated here.

Further, each pixel circuit is also configured with a column control line COL, and the analog signal output by the pixel circuit can be transmitted to the conversion circuit 141 through the column control line COL. The readout circuit 1113 includes an input terminal and an output terminal, wherein the input terminal is connected to the floating diffusion area, and the output terminal is connected to the column control line COL, and is used to transmit the analog signal corresponding to the charge transferred to the floating diffusion area through the column control line COL is output to the conversion circuit 141 .

FIG. 5 is a schematic diagram of the arrangement of pixels in a subunit according to an embodiment of the present application. Wherein, the sub-unit 111 can be 16 pixels in 4 rows and 4 columns, and the arrangement is as follows:

W represents a panchromatic pixel; A represents a first color pixel among the plurality of color pixels; the panchromatic pixel W is arranged in the first diagonal direction D1, and the color pixel is arranged in the second diagonal direction D2.

For the convenience of description, in the embodiment of the present application, the subunit as shown in FIG. 5 is taken as an example, which includes 16 pixels in four rows and four columns. As shown in FIGS. 6-8 , the subunit 111 includes eight panchromatic pixels W and eight color pixels A. The first pixel circuit 101 may include eight first photoelectric conversion elements 1111 , eight first transfer transistors 1112 , a first floating diffusion region FD1 and a first readout circuit 1113 . The first pixel circuit 101 can also be configured with eight first exposure control lines for providing exposure control signals, and each first exposure control line can correspond to gates of eight first transfer transistors (TG2, TG4, TG5, TG7, TG10, TG12, TG13, TG15) connections. When a pulse of an effective level (for example, VPIX level) is transmitted to the gate of the first transfer transistor 1112 through the first exposure control line, the first transfer transistor 1112 is turned on, and the first transfer transistor 1112 converts the first photoelectric conversion element to 1111 The photoelectrically converted charges are transferred to the corresponding first floating diffusion region FD1. The second pixel circuit 102 may include eight second photoelectric conversion elements 1111', eight second transfer transistors 1112', a second floating diffusion region FD2, and a second readout circuit 1113'. The second pixel circuit 102 can also be configured with eight second exposure control lines for providing exposure control signals, and each second exposure control line can correspond to the gates (TG1, TG3, TG6, TG8, TG9, TG11, TG14, TG16) connections. When the pulse of the effective level (for example, VPIX level) is transmitted to the gate of the second transfer transistor 1112' through the second exposure control line, the second transfer transistor 1112' is turned on, and the second transfer transistor 1112' turns the second Charges photoelectrically converted by the photoelectric conversion element 1111' are transferred to the corresponding second floating diffusion region FD2.

The readout circuit 1113 includes a reset transistor 11131 , an amplifying transistor 11132 (also referred to as a follower transistor), and a selection transistor 11133 . The first terminal of the reset transistor 11131 is connected to the corresponding floating diffusion area, the second terminal of the reset transistor 11131 is used to receive the reset voltage, and the control terminal of the reset transistor 11131 is used to receive the reset control signal, and is used to reset the floating diffusion according to the reset control signal. district. The control terminal of the amplifying transistor 11132 is connected to the floating diffusion region, and the first terminal of the amplifying transistor 11132 is connected to the second terminal of the reset transistor 11131 for amplifying the charge in the floating diffusion region. The first end of the selection transistor 11133 is connected to the second end of the amplification transistor 11132, the second end of the selection transistor 11133 is connected to the corresponding column control line COL, the control end of the selection transistor 11133 is used to receive the selection control signal, and is used to select The control signal outputs the analog signal corresponding to the amplified charge to the column control line COL, so as to be transmitted to the corresponding analog-to-digital conversion through the column control line COL. For the convenience of description, in the embodiment of the present application, the transistors in the pixel circuit are MOS transistors as an example for description.

The drain of the reset transistor 11131 is connected to the power supply VPIX. The source of the reset transistor 11131 is connected to the corresponding floating diffusion FD. Before charges are transferred from the corresponding photoelectric conversion elements to the floating diffusion region FD, a pulse of effective reset level is transmitted to the gate RG of the reset transistor 11131 via the reset line, and the reset transistor 11131 is turned on. The reset transistor 11131 resets the floating diffusion FD to the subunit 111 power supply VPIX. The gates of the amplification transistors 11132 are connected to the corresponding floating diffusions FD. The drain of the amplification transistor 11132 is connected to the power supply VPIX. After the floating diffusion FD is reset by the reset transistor 11131 , the amplifying transistor 11132 outputs an analog signal corresponding to the reset level and the charge via the selection transistor 11133 . After the charge of the photodiode is transferred by the transfer transistor 1113 , the amplifying transistor 11132 outputs an analog signal to the column control line COL through the selection transistor 11133 , so as to be transferred to the corresponding analog-to-digital conversion via the column control line COL.

For ease of description, the working principle of the addition mode in the full-resolution output mode and the combined output mode will be described by taking the image sensor shown in FIGS. 7 and 8 as an example.

Wherein, the full-resolution output mode can be understood as that the conversion circuit 141 and the two pixel circuits jointly read out the digital signal converted from the analog signal in units of pixels.

Full resolution output mode: within the same exposure time, control the gates TG1 and TG2 of the transfer transistor 1113 to input a high level, the corresponding transfer transistor 1113 is turned on, and the charge generated by the pixel A2 is transferred to the first floating diffusion region FD1, and the pixel Charges generated by W1 are transferred to the second floating diffusion FD2. Subsequently, control the gates TG1 and TG2 of the transfer transistor 1113 to input a low level, and the corresponding transfer transistor 1113 is turned off, and the charge in the first floating diffusion region FD1 passes through the amplifying transistor 11132, and the converted analog signal passes through the first column The control line COL1 is input to the first analog-to-digital converter 1411, and the digital signal corresponding to the charge generated by the pixel A2 is read out after the analog-to-digital conversion; the charge in the second floating diffusion region FD2 is converted into an analog signal by the amplifier transistor 11132 It is input to the second analog-to-digital converter 1412 through the second column control line COL2, and the digital signal corresponding to the charge generated by the pixel W1 is read out after analog-to-digital conversion. Then control the gates TG3 and TG4 of the transfer transistor 1113 to input a high level, similar to the readout method of the pixels A2 and W1, the digital signals corresponding to the charges generated by the pixels W3 and A4 can be read out, and so on, corresponding to The digital signal corresponding to the charge generated by each pixel in the subunit 111 is read out. Wherein, the process of reading out pixel data in the full-resolution output mode may be shown in FIG. 9 .

The addition mode can be understood as: read out after performing analog-to-digital conversion on the total charge accumulated in the corresponding floating diffusion region of at least two pixels with the same color in the same subunit 111 . Read out after performing analog-to-digital conversion on the first total charge accumulated in the corresponding floating diffusion region of at least two color pixels in the same subunit 111, and read out the at least two panchromatic pixels in the corresponding floating diffusion region in the same subunit 111 The second total charge accumulated in the diffusion area is read out after analog-to-digital conversion.

In the embodiment of the present application, the addition mode can be divided into a plurality of addition modes of different levels according to the total charges accumulated by n pixels of the same color in the corresponding floating diffusion region within the same exposure time. Take m=4 and n=8 (that is, n=m ² /2) as an example for illustration. Wherein, when n<m ² /2, the corresponding level is the first-level addition mode, that is, the first-level addition mode in the first-level combined output mode. When n=m ² /2, the corresponding level is the second-level addition mode, that is, the first-level addition mode in the second-level combined output mode.

The first-stage addition mode: within the same exposure time, control the gates TG1, TG6, TG2, and TG5 of the transfer transistor 1113 to input high levels at the same time, and the corresponding transfer transistor 1113 is turned on, and the two color pixels of pixels A2 and A5 generate The charges generated by the two full-color pixels W1 and W6 are transferred to the second floating diffusion region FD2 for accumulation. Subsequently, the gates TG1, TG6, TG2, and TG5 of the transfer transistor 1113 are controlled to input a low level at the same time, and the corresponding transfer transistor 1113 is turned off, and the charge accumulated in the first floating diffusion region FD1 is converted into an analog signal by the amplifier transistor 11132 The first column control line COL1 is input to the first analog-to-digital converter 1411, and the digital signal corresponding to the charge accumulated by the pixels A2 and A5 is read out after the analog-to-digital conversion; the charge in the second floating diffusion region FD2 is passed through the amplifying transistor After 11132, the converted analog signal is input to the second analog-to-digital converter 1412 through the second column control line COL2, and the digital signal corresponding to the charge accumulated by pixels W1 and W6 is read out after analog-to-digital conversion. By analogy, the digital signal corresponding to the charges accumulated by two pixels of the same color in the same exposure time in the sub-unit 111 can be correspondingly read out. Wherein, the process of reading out pixel data using the first-level addition mode may be shown in FIG. 10 .

It should be noted that in the first-stage addition mode, the level signals loaded on the gates of multiple different transfer transistors can also be controlled at the same time, so that the charges of multiple pixels of the same color are transferred to the same floating diffusion region . In the process of executing the first-level addition mode, for the same subunit, the pixel data read out have the same resolution in the row direction and the column direction.

In one of the embodiments, the addition mode may also be: read out after performing analog-to-digital conversion on the total charge accumulated in the corresponding floating diffusion region of all pixels of the same color in the same subunit. The addition mode may correspond to the second-level addition mode when n=m2/2.

The second-level addition mode: within the same exposure time, control the gate TG2, TG4, TG5, TG7, TG10, TG12, TG13, TG15, TG1, TG3, TG6, TG8, TG9, TG11, TG14 of the transfer transistor 1113 , TG16 input a high level at the same time, the corresponding transfer transistor 1113 is turned on, and the charges generated by the eight color pixels of pixels A2, A4, A5, A7, A10, A12, A13, and A15 are simultaneously transferred to the first floating diffusion area FD1 for accumulation, The charges generated by the eight full-color pixels W1, W3, W6, W8, W9, W11, W14, and W16 are transferred to the second floating diffusion region FD2 for accumulation. Subsequently, the gates TG2, TG4, TG5, TG7, TG10, TG12, TG13, TG15, TG1, TG3, TG6, TG8, TG9, TG11, TG14, and TG16 of the transfer transistor 1113 are controlled to input low levels at the same time, corresponding to the transfer transistor 1113 is turned off, the charge accumulated in the first floating diffusion region FD1 passes through the amplifying transistor 11132, and the converted analog signal is input to the first analog-to-digital converter 1411 through the first column control line COL1, and the pixel is read out after analog-to-digital conversion A2, A4, A5, A7, A10, A12, A13, and A15 are the digital signals corresponding to the accumulated charges; the charges in the second floating diffusion area FD2 are converted into analog signals through the second column control after passing through the amplifier transistor 11132 The line COL2 is input to the second analog-to-digital converter 1412 , and digital signals corresponding to the accumulated charges of pixels W1 , W3 , W6 , W8 , W9 , W11 , W14 , and W16 are read out after analog-to-digital conversion. Wherein, the process of reading out pixel data using the second-level addition mode may be shown in FIG. 11 .

As shown in FIG. 12, in one embodiment, the first pixel circuit further includes: a first switch unit, a plurality of first ends of the first switch unit are respectively connected to the second ends of the first transfer transistors 1112, the first A plurality of second ends of a switch unit are respectively connected to the first floating diffusion region FD1 and the second floating diffusion region FD2; A transfer path between the floating diffusion region FD1 and the second floating diffusion region FD2. The second pixel circuit further includes a second switch unit, the multiple first terminals of the second switch unit are respectively connected to the second terminals of the second transfer transistors 1112 ′, and the multiple second terminals of the second switch unit are respectively connected to the first The floating diffusion FD1 and the second floating diffusion FD2 are connected. The second switch unit is used to selectively conduct the transfer paths between the second terminal of any second transfer transistor 1112' and the first floating diffusion region FD1 and the second floating diffusion region FD2 respectively. In the embodiment of the present application, the transfer transistor 1113 connected to the first photoelectric conversion element 1111 is the first transfer transistor 1112, and the transfer transistor 1113 connected to the second photoelectric conversion element 1111' is the second transfer transistor 1112'.

In one of the embodiments, if the subunit includes m rows and m columns of pixels, its first switch unit includes m first switches, and the first ends of the first switches are respectively connected to the second ends of the first transfer transistors 1112, The two second ends of the first switch are connected to the first floating diffusion region FD1 and the second floating diffusion region FD2 respectively. The second switch unit includes m second switches, the first ends of the second switches are respectively connected to the second ends of the second transfer transistors 1112', and the two second ends of the second switches are respectively connected to the first floating diffusion region FD1 , and the second floating diffusion region FD2 is connected. For ease of description, m=4 is taken as an example for descriptive description. Wherein, the first unit may include four first switches, for example, may be respectively marked as first switches S1, S4, S5, and S8. Each first switch is a single pole double throw switch. The single terminals of the first switches S1, S4, S5, and S8 are connected to the first transfer transistors 1112 of the first row, the first transfer transistors 1112 of the second row, the first transfer transistors 1112 of the third row, and the fourth transfer transistors of the third row respectively. The first transfer transistors 1112 in the row are connected in one-to-one correspondence, and the two selection terminals of the first switches S1 , S4 , S5 , and S8 are respectively connected in one-to-one correspondence with the first floating diffusion region FD1 and the second floating diffusion region FD2 .

The second switch unit may include four second switches, for example, may be respectively marked as second switches S2, S3, S6, and S7. Each first switch is a single pole double throw switch. Correspondingly, the single terminals of the second switches S2, S3, S6, and S7 are connected to the second transfer transistors 1112' of the first row, the second transfer transistors 1112' of the second row, and the second transfer transistors of the third row respectively. The transistor 1112' and the second transfer transistors 1112' in the fourth row are connected in one-to-one correspondence, and the two selection ends of the second switches S2, S3, S6, and S7 are connected to the first floating diffusion region FD1 and the second floating diffusion region FD2 respectively. One-to-one connection.

Optionally, the first switch unit may also be a multi-pole multi-throw switch, and the second switch unit may also be a multi-pole multi-throw switch. In the embodiment of the present application, the combination of the first switch unit and the second switch unit is not limited to the above examples, and may also be a combination of other types of switches.

In one of the embodiments, the first pixel circuit and the second pixel circuit are further configured with a first transfer control line and a second transfer control line, wherein a plurality of input terminals of the first transfer control line (for example,

contacts

2, 4 , 6, 8) are respectively connected to the first switch and the second switch; the output end of the first transfer control line is connected to the first floating diffusion region FD1. A plurality of input ends (for example,

contacts

1, 3, 5, 7) of the second transfer control line are respectively connected to the first switch and the second switch; the output end of the second transfer control line is connected to the second floating diffusion area FD2 connect.

For ease of description, the image sensor shown in FIG. 12 is taken as an example to describe the working principle of the addition mode in the full-resolution output mode and the combined output mode.

Full resolution output mode: within the same exposure time, control the first switch S1 to connect to contact 2, the second switch S2 to connect to contact 1, the second switch S3 to connect to contact 3, and the first switch S4 to connect to contact Point 4, the first switch S5 is connected to contact 6, the second switch S6 is connected to contact 5, the second switch S7 is connected to contact 7, and the first switch S8 is connected to contact 8. For the data readout of the charge generated by each pixel in the subunit 111 , reference may be made to the full-resolution output mode in the foregoing embodiments, which will not be repeated here.

The first addition mode in the combined output mode: within the same exposure time, control the first switch S1 to connect to contact 2, the second switch S2 to connect to contact 1, the second switch S3 to connect to contact 3, the first The switch S4 is connected to the contact 4, the first switch S5 is connected to the contact 6, the second switch S6 is connected to the contact 5, the second switch S7 is connected to the contact 7, and the first switch S8 is connected to the contact 8. For data readout of charges accumulated and generated by at least two pixels of the same color in the subunit 111 , reference may be made to the addition mode in the foregoing embodiments, which will not be repeated here.

As shown in FIG. 13, in one embodiment, the conversion circuit 141 further includes a third switch unit 1413, the first end of the third switch unit 1413 is connected to the output end of one of the analog-to-digital converters, and the third switch unit 1413 The second terminal of is connected to the output terminal of another analog-to-digital converter. Wherein, the third switch unit 1413 may include a switch S10, wherein the first end of the switch S10 is used to connect to the output end of the first analog-to-digital converter 1411, and the second end of the switch S10 is used to connect to the output end of the second analog-to-digital converter. 1412 output connection. When the third switch unit 1413 is turned on, digital averaging can be performed on the first digital signal output from the first analog-to-digital converter 1411 and the second digital signal output from the second mode converter.

Based on the image sensor as shown in FIG. 13 , the conversion circuit 141 is also used to read out the digital signal converted from the analog signal based on the full resolution output mode or combined output mode together with the first pixel circuit and the second pixel circuit. Wherein, in addition to the addition mode in the foregoing embodiments, the combined output mode may also include a digital average mode and a first mixing mode.

Wherein, the digital average mode can be understood as: respectively performing analog-to-digital conversion on the charges generated by at least two pixels with the same color in the same subunit 111 in time division, and reading out after averaging the converted digital signals. The digital average mode can also be understood as: respectively performing analog-to-digital conversion on the charges generated by time-sharing of at least two color pixels in the same subunit 111, and reading out after averaging the converted digital signals, and performing an average on the same subunit 111. The charges generated by the at least two full-color pixels in the unit 111 in time division are respectively subjected to analog-to-digital conversion, and the converted digital signals are averaged and then read out. Wherein, the digital average mode can be used as one of the first-stage combined output modes.

The first mixing mode can be understood as: the first digital signal output after analog-to-digital conversion of the first analog signal accumulated in the floating diffusion area by the first part of pixels in the same subunit 111, and the second part of pixels in the same subunit 111 The second analog signal accumulated in the floating diffusion area is read out after the analog-to-digital conversion and the second digital signal is averaged; wherein the colors of the first part of the pixels and the second part of the pixels are the same, and the total number of pixels of all part of the pixels is the same as that of the color pixels or equal total number of panchromatic pixels. Wherein, the first blending mode can be used as one of the second-stage combined output modes.

For ease of description, the working principles of the digital average mode and the first mixing mode will be described by taking the image sensor shown in FIG. 13 as an example.

Digital average mode: control the first switch S1 to connect to contact 2, the second switch S2 to connect to contact 2, the second switch S3 to connect to contact 3, the first switch S4 to connect to contact 3, the first switch S5 to connect To the contact 6, the second switch S6 is connected to the contact 5, the second switch S7 is connected to the contact 7, the first switch S8 is connected to the contact 7, and controls the switch S10 to conduct. During the same exposure time, control the gates TG2 and TG5 of the transfer transistor 1113 to input a high level, the corresponding transfer transistor 1113 is turned on, the charge generated by the pixel A2 is transferred to the first floating diffusion region FD1, and the charge generated by the pixel A5 is transferred to The second floating diffusion FD2. Subsequently, control the gates TG2 and TG5 of the transfer transistor 1113 to input a low level, and the corresponding transfer transistor 1113 is turned off, and the charge in the first floating diffusion region FD1 passes through the amplifying transistor 11132, and the converted analog signal passes through the first column The control line COL1 is input to the first analog-to-digital converter 1411, and the first digital signal corresponding to the charge generated by the pixel A2 is read out after the analog-to-digital conversion; the charge in the second floating diffusion region FD2 is converted into The analog signal is input to the second analog-to-digital converter 1412 through the second column control line COL2, and the second digital signal corresponding to the charge generated by the pixel A5 is read out after analog-to-digital conversion. After being connected through the switch S10, a digital average (digital average) signal of the first digital signal and the second digital signal can be correspondingly output. Other color pixels in a subunit can also use this digital average mode to read out their corresponding digital average signals, and panchromatic pixels in a subunit can also use this digital average mode to read out their corresponding digital average signals. Let me repeat. Wherein, the process of reading out the pixel data by adopting the digital average mode can be shown in FIG. 10 .

First mixed mode: control first switch S1 connected to contact 2, second switch S2 connected to contact 2, second switch S3 connected to contact 4, first switch S4 connected to contact 4, first switch S5 connected to contact 6, the second switch S6 is connected to contact 5, the second switch S7 is connected to contact 7, the first switch S8 is connected to contact 7, and controls switch S10 to conduct. During the same exposure time, the gates TG2, TG4, TG5, TG7, TG10, TG12, TG13, and TG15 of the transfer transistor 1113 are controlled to input high levels at the same time, and the corresponding transfer transistor 1113 is turned on, and the pixels A2, A4, A5, and A7 The charges generated by the four color pixels are simultaneously transferred to the first floating diffusion region FD1 for accumulation, and the charges generated by the pixels A10, A12, A13, and A15 are transferred to the second floating diffusion region FD2 for accumulation. Subsequently, the gates TG2, TG4, TG5, TG7, TG10, TG12, TG13, and TG15 of the transfer transistor 1113 are controlled to input a low level at the same time, and the corresponding transfer transistor 1113 is turned off, and the charge accumulated in the first floating diffusion region FD1 is passed through the amplifying transistor After 11132, the converted analog signal is input to the first analog-to-digital converter 1411 through the first column control line COL1, and after the analog-to-digital conversion, the second digital corresponding to the accumulated charge of the pixels A2, A4, A5, and A7 is read out. Signal; after the charge in the second floating diffusion region FD2 is passed through the amplifier transistor 11132, the converted analog signal is input to the second analog-to-digital converter 1412 through the second column control line COL2, and the pixels A10 and A12 are read out after the analog-to-digital conversion , A13 , and A15 are the second digital signal corresponding to the accumulated charges. After being connected through the switch S10, a digital average (digital average) signal of the first digital signal and the second digital signal can be correspondingly output. Based on the aforementioned first mixing mode, the digital average signal corresponding to the charges accumulated by the eight panchromatic color pixels in the same exposure time in the sub-unit 111 can be correspondingly read out. Wherein, the process of reading pixel data by using the first mixing mode may be as shown in FIG. 11 .

As shown in FIG. 14 and FIG. 15 , in one embodiment, the conversion circuit 141 further includes a fourth switch unit 1414 . Wherein, the first end of the fourth switch unit 1414 is connected to the readout circuit 1113 of the first pixel circuit, and the second end of the fourth switch unit 1414 is connected to the readout circuit 1113 of the second pixel circuit. The fourth switch unit 1414 may include a switch S9. Wherein, the first end of the switch S9 is connected to the first end of the selection transistor 11133 in the first readout circuit 1113, and the second end of the switch S9 is connected to the first end of the selection transistor 11133 in the second readout circuit 1113′ . In the embodiment of the present application, the fourth switch unit 1414 is used to selectively turn on or turn off the averaging path between the two readout circuits 1113 . That is, when the fourth switch unit 1414 turns on the average path between the first readout circuit 1113 and the second readout circuit 1113', the first analog signal output by the first readout circuit 1113 and the second readout Analog averaging is performed on the second analog signal output by the output circuit 1113'.

Based on the image sensor as shown in Figs. 14 and 15, the conversion circuit 141 can also work with the first pixel circuit 101 and the second pixel circuit 102 to read out the digital signal converted from the analog signal based on the full resolution output mode or combined output mode. Wherein, in addition to the addition mode in the foregoing embodiments, the combined output mode may also include an analog average mode and a second mixing mode.

The analog average mode is: average the charge numbers corresponding to two analog signals generated by time-sharing of at least two pixels with the same color in the same subunit, and read them out after analog-to-digital conversion. Wherein, the analog average mode can be used as one of the first-stage combined output modes.

The second mixing mode is: average the first analog signal accumulated in the floating diffusion region by the first part of pixels in the same subunit, and the second analog signal accumulated in the floating diffusion region by the second part of pixels in the same subunit, and the modulus Read out after conversion; wherein the first part of pixels and the second part of pixels have the same color, and the total number of pixels of all part of pixels is equal to the total number of color pixels or panchromatic pixels. Wherein, the second mixing mode can be used as one of the second-stage combined output modes.

For ease of description, the working principles of the analog average mode and the second mixed mode will be described by taking the image sensor shown in FIGS. 14 and 15 as an example.

Analog averaging mode: control the first switch S1 connected to contact 2, the second switch S2 connected to contact 2, the second switch S3 connected to contact 3, the first switch S4 connected to contact 3, the first switch S5 connected To the contact 6, the second switch S6 is connected to the contact 6, the second switch S7 is connected to the contact 7, the first switch S8 is connected to the contact 7, and the switch S9 is controlled to conduct. If the image output sensor includes a switch S10, the switch S10 is controlled to be turned off. During the same exposure time, control the gates TG1 and TG6 of the transfer transistor 1113 to input a high level, the corresponding transfer transistor 1113 is turned on, the charge generated by the pixel W1 is transferred to the first floating diffusion region FD1, and the charge generated by the pixel W6 is transferred to The second floating diffusion FD2. Control the gates TG1 and TG6 of the transfer transistor 1113 to input a low level, and the corresponding transfer transistor 1113 is turned off, and the charge in the first floating diffusion region FD1 is converted into the first analog signal after passing through the amplifying transistor 11132, and the second floating diffusion The charge in the region FD2 is converted into a second analog signal after passing through the amplifying transistor 11132 . Since the switch S9 connects the first readout circuit 1113 and the second readout circuit 1113', the first analog signal and the second analog signal can pass through the first analog-to-digital converter 1411 or the second analog-to-digital converter 1411 or the second analog-to-digital converter 1411 after analog averaging. Digital converter 1412 output. Other panchromatic pixels and color pixels in the subunit 111 can also use this analog average mode to read out the digital average signal corresponding to their analog average signal, which will not be repeated here. Wherein, the process of reading out the pixel data by adopting the analog average mode may be shown in FIG. 10 .

Second mixed mode: control first switch S1 connected to contact 2, second switch S2 connected to contact 2, second switch S3 connected to contact 4, first switch S4 connected to contact 4, first switch S5 connected to contact 5, the second switch S6 is connected to contact 5, the second switch S7 is connected to contact 7, the first switch S8 is connected to contact 7, and the switch S9 is controlled to conduct. If the image output sensor includes a switch S10, the switch S10 is controlled to be turned off. During the same exposure time, the gates TG1, TG3, TG6, TG8, TG9, TG11, TG14, and TG16 of the transfer transistor 1113 are controlled to input high levels at the same time, and the corresponding transfer transistor 1113 is turned on, and the pixels W1, W3, W6, and W8 Charges generated by the four full-color pixels are simultaneously transferred to the first floating diffusion region FD1 for accumulation, and charges generated by pixels W9, W11, W14, and W16 are transferred to the second floating diffusion region FD2 for accumulation. Subsequently, the gates TG1, TG3, TG6, TG8, TG9, TG11, TG14, and TG16 of the transfer transistor 1113 are controlled to input a low level at the same time, and the corresponding transfer transistor 1113 is turned off, and the charge in the first floating diffusion region FD1 is passed through the amplification transistor After 11132, it is converted into the first analog signal, and the charges in the second floating diffusion region FD2 are converted into the second analog signal after passing through the amplifying transistor 11132 . Since the switch S9 connects the first readout circuit 1113 and the second readout circuit 1113', the first analog signal and the second analog signal can pass through the first analog-to-digital converter 1411 or the second analog-to-digital converter 1411 or the second analog-to-digital converter 1411 after analog averaging. Digital converter 1412 output. All the color pixels in the subunit 111 can also use the second mixing mode to read out the digital average signal corresponding to their analog average signal, which will not be repeated here. Wherein, the process of reading pixel data by using the second mixing mode may be as shown in FIG. 11 .

Based on the image sensor shown in FIG. 15 , the conversion circuit 141 can also read out the digital signal converted from the analog signal based on the full-resolution output mode or combined output mode together with the first pixel circuit and the second pixel circuit. Wherein, besides the addition mode, the analog average mode, the digital average mode, the first mixed mode, and the second mixed mode in the foregoing embodiments, the combined output mode also includes a third mixed mode.

The third mixing mode is: averaging the first analog signal accumulated in the floating diffusion area of the first sub-part of pixels in the same sub-unit, and the second analog signal accumulated in the floating diffusion area of the second sub-part of pixels in the same sub-unit, The first digital signal is output through analog-to-digital conversion; the third analog signal accumulated in the floating diffusion area by the third sub-part of the pixels in the same subunit, and the fourth analog signal accumulated in the floating diffusion area by the fourth sub-part of the pixels in the same subunit The signal is averaged, and the second digital signal is output through analog-to-digital conversion, and the first digital signal and the second digital signal are averaged and then read out; wherein the first sub-section of pixels, the second sub-section of pixels, the third sub-section of pixels, The pixels in the fourth subsection have the same color, and the total number of pixels in all subsections is equal to the total number of color pixels or panchromatic pixels. The third mixing mode can be used as one of the second-level combined output modes.

For ease of description, the working principle of the third hybrid mode will be described by taking the image sensor shown in FIG. 15 as an example.

The third hybrid mode: control the first switch S1 connected to contact 2, the second switch S2 connected to contact 2, the second switch S3 connected to contact 4, the first switch S4 connected to contact 4, the first switch S5 Connected to the contact 5, the second switch S6 is connected to the contact 5, the second switch S7 is connected to the contact 7, the first switch S8 is connected to the contact 7, and controls the conduction of the switch S9 and the conduction of the switch S10. During the first exposure time, the gates TG1, TG3, TG9, and TG11 of the transfer transistor 1113 are controlled to input a high level at the same time, and the corresponding transfer transistor 1113 is turned on, and the charges generated by the two full-color pixels of pixels W1 and W3 are simultaneously transferred to The first floating diffusion region FD1 performs accumulation, and the charges generated by the two full-color pixels of pixels W9 and W11 are transferred to the second floating diffusion region FD2 for accumulation. Subsequently, the gates TG1, TG3, TG9, and TG11 of the transfer transistor 1113 are controlled to input a low level at the same time, and the corresponding transfer transistor 1113 is turned off, and the charge in the first floating diffusion region FD1 is converted into the first An analog signal, the charge in the second floating diffusion region FD2 is converted into a second analog signal after passing through the amplifying transistor 11132 . Since the switch S9 connects the first readout circuit 1113 and the second readout circuit 1113', the conduction state of the selection amplifier can be controlled, so that the analog averaged analog signal can output the first digital signal through the first analog-to-digital converter 1411 . Then, after the reset transistor 11131 is reset at a high level, charges in the first floating diffusion region FD1 and the second floating diffusion region FD2 are cleared. During the second exposure time, the gates TG6, TG8, TG14, and TG16 of the transfer transistor 1113 are controlled to input a high level at the same time, and the corresponding transfer transistor 1113 is turned on, and the charges generated by the two full-color pixels of pixels W6 and W8 are simultaneously transferred to The first floating diffusion region FD1 performs accumulation, and the charges generated by the two full-color pixels of pixels W14 and W16 are transferred to the second floating diffusion region FD2 for accumulation. Subsequently, the gates TG6, TG8, TG14, and TG16 of the transfer transistor 1113 are controlled to input a low level at the same time, and the corresponding transfer transistor 1113 is turned off, and the charges in the first floating diffusion region FD1 are converted into third For the analog signal, the charge in the second floating diffusion region FD2 is converted into a fourth analog signal after passing through the amplifying transistor 11132 . Since the switch S9 connects the first readout circuit 1113 and the second readout circuit 1113', the conduction state of the selection amplifier can be controlled, so that the averaged analog signal passes through the second analog-to-digital converter 1412 to output the second digital signal . Since the switch S10 is connected, a digital average signal of the first digital signal and the second digital signal can be correspondingly output. The color pixels in the sub-units can also use this digital average mode to read out their corresponding digital average signal. Here, no more details. Wherein, the process of reading pixel data by using the third mixing mode may be as shown in FIG. 11 .

The image sensor in the embodiment of the present application can support the readout of the charge data of each pixel in each subunit in the full-resolution output mode, the first-level combined output mode, or the second-level combined output mode, which can expand the image sensor. The flexibility of the output mode can be applied to more usage scenarios. It should be noted that, during the process of controlling the readout of the charge data of each pixel in each subunit in the full-resolution output mode, the first-level combined output mode or the second-level combined output mode, the control logic is not limited to the above-mentioned For example, it only needs to meet the resolution in the row direction and the column direction of the pixel data read out based on the full-resolution output mode, the first-level combined output mode or the second-level combined output mode for each pixel in the same subunit Just the same.

Exemplarily, for a picture shooting scene, when it is necessary to capture images of high-definition scenes (for example, scenes with more textures, such as grass, etc.) or high-brightness scenes (for example, outdoors on a sunny day), the image sensor can be controlled to operate in full-resolution mode Data is read out from the pixel array for full-size image capture. When it is necessary to collect images of low-brightness scenes (for example, indoor scenes or outdoors on cloudy days), the image sensor can be controlled to read out the data of the pixel array in a medium-resolution output mode (for example, the first-level combined output mode) to perform Picture shooting; when it is necessary to collect an image of a dark scene (for example, at night), the image sensor can be controlled to read out the output mode of the pixel array with a high light input amount and a high signal-to-noise ratio (for example, the second-level combined output mode) data for image capture.

Exemplarily, for a video shooting scene, when you need to shoot 4K2K video, you can switch to the first-level combined output mode to read out the data of the pixel array; when you need to shoot 1080P video, you can switch to the second-level combined output mode to read out Data for the pixel array. As for the general preview mode, the data of the pixel array can be read out in the second-level combined output mode.

As shown in FIG. 16 , the embodiment of the present application also provides a camera assembly. Wherein, the camera assembly 20 includes the image sensor 10 and the lens 21 of any embodiment of the present application. The lens 21 is used to image the image on the image sensor 10 , for example, the light of the subject is imaged to the image sensor 10 through the lens 21 , and the image sensor 10 is arranged on the focal plane of the lens 21 . The camera assembly 20 may also include circuit components 22 . The circuit part 22 is used to obtain electric energy and transmit data with the outside, for example, the circuit part can be connected with the power supply of my department to obtain electric energy, and can also be connected with a memory or a processor to transmit image data or control data.

Wherein, the camera assembly 20 can be arranged on the back of the mobile phone as a rear camera. Understandably, the camera assembly 20 can also be arranged on the front of the mobile phone as a front camera.

As shown in FIG. 17 , the embodiment of the present application also provides a mobile terminal. The mobile terminal 100 includes the camera assembly 20 and the casing 80 of any embodiment of the present application. The camera assembly 20 is combined with the casing 80 . The camera head assembly 20 is arranged on the casing 80, the casing 80 includes a middle frame and a backboard, and the camera head assembly 20 is fixedly arranged on the middle frame or the backboard.

The mobile terminal 100 also includes a processor and a memory connected through a system bus. Among them, the processor is used to provide computing and control capabilities to support the operation of the entire electronic device. The memory may include non-volatile storage media and internal memory. Nonvolatile storage media store operating systems and computer programs. The internal memory provides a high-speed running environment for the operating system computer program in the non-volatile storage medium. The electronic device can be any terminal device such as mobile phone, tablet computer, PDA (PeAsonal Digital Assistant, personal digital assistant), POS (Point of Sales, sales terminal), vehicle-mounted computer, wearable device, etc.

The above-mentioned embodiments only express several implementation modes of the present application, and the description thereof is relatively specific and detailed, but should not be construed as limiting the patent scope of the present application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the scope of protection of the patent application should be based on the appended claims.

Claims

An image sensor comprising:

A pixel array comprising a plurality of subunits, each of the subunits comprising a plurality of color pixels and a plurality of panchromatic pixels, wherein the color pixels have a narrower spectral response than the panchromatic pixels; wherein the subunits The unit includes two pixel circuits, wherein one of the pixel circuits includes a plurality of first photoelectric conversion elements corresponding to the plurality of color pixels, and the other pixel circuit includes a plurality of first photoelectric conversion elements corresponding to the plurality of panchromatic pixels. A plurality of second photoelectric conversion elements arranged in one-to-one correspondence, wherein the pixel circuit is used to transfer the charge generated by at least one first photoelectric conversion element or at least one second photoelectric conversion element of the subunit to the corresponding floating diffusion area, and output an analog signal corresponding to the accumulated charge in the floating diffusion area; and

A plurality of conversion circuits are respectively connected to a plurality of the sub-units in one-to-one correspondence, wherein the conversion circuits include two analog-to-digital converters respectively connected to the two pixel circuits in a one-to-one correspondence, and the conversion circuits are used for and at least one of the two pixel circuits to read out the digital signal converted from the analog signal based on a full-resolution output mode or a combined output mode, wherein the full-resolution output mode is used for pixel-based The digital signal is read out, and the combined output mode is used to read out the digital signal in units of at least two pixels having the same color in the subunit.
The image sensor according to claim 1, wherein two of said pixel circuits comprise:

a first pixel circuit, including a first floating diffusion region, and all the color pixels in the same subunit share the first floating diffusion region; and

The second pixel circuit includes a second floating diffusion area, and all the panchromatic pixels in the same subunit share the second floating diffusion area.
The image sensor according to claim 2, wherein,

The first pixel circuit is configured to transfer the first charge generated by at least one of the first photoelectric conversion elements in the same subunit to the first floating diffusion area for accumulation, and output the first charge in the first floating diffusion area a first analog signal corresponding to the first charge;

The second pixel circuit is configured to transfer the second charge generated by at least one second photoelectric conversion element in the same subunit to a second floating diffusion area for accumulation, and output the second charge in the second floating diffusion area a second analog signal corresponding to the second charge;

The two analog-to-digital converters include a first analog-to-digital converter and a second mode converter, wherein a plurality of the first analog-to-digital converters are respectively connected to a plurality of the first pixel circuits in a one-to-one correspondence, and a plurality of Each of the second analog-to-digital converters is respectively connected to a plurality of the second pixel circuits in one-to-one correspondence; the conversion circuit, the first pixel circuit, and the second pixel circuit are based on a full-resolution output mode or combined output. The mode reads out digital signals converted from the first analog signal and the second analog signal.
The image sensor according to claim 2, wherein each pixel circuit is configured with a column of control lines, wherein the pixel circuit comprises:

a plurality of transfer transistors, the first terminals of the transfer transistors are connected to the corresponding photoelectric conversion elements, the control terminals of the transfer transistors are used to receive transfer control signals, and the transfer transistors are used to control the transfer control signals Next, the charge generated by the photoelectric conversion element is transferred to the floating diffusion region;

A readout circuit, including an input terminal and an output terminal, wherein the input terminal is connected to the floating diffusion area, and the output terminal is connected to the column control line, for transferring the charges transferred to the floating diffusion area output to the conversion circuit through the column control line.
The image sensor according to claim 4, wherein the first pixel circuit further comprises: a first switch unit, a plurality of first terminals of the first switch unit are respectively connected to the second terminals of the first transfer transistors , the plurality of second ends of the first switch unit are respectively connected to the first floating diffusion region and the second floating diffusion region;

The second pixel circuit further includes a second switch unit, the multiple first terminals of the second switch unit are respectively connected to the second terminals of the second transfer transistors, and the multiple second terminals of the second switch unit respectively connected to the first floating diffusion region and the second floating diffusion region; wherein, the transfer transistor connected to the first photoelectric conversion element is the first transfer transistor, and is connected to the second photoelectric conversion element The transfer transistor is the second transfer transistor.
The image sensor according to claim 5, wherein the number of the first transfer transistors is equal to the number of the first photoelectric conversion elements.
The image sensor according to claim 5, wherein the subunit comprises m rows and m columns of pixels, wherein the panchromatic pixels are arranged in the first diagonal direction, and the color pixels are arranged in the second diagonal direction Line direction, the first diagonal direction is different from the second diagonal direction; m is an integer greater than or equal to 2.
The image sensor according to claim 7, wherein the first switch unit comprises m first switches, and the first ends of the first switches are respectively connected to the second ends of the first transfer transistors, so The two second ends of the first switch are respectively connected to the first floating diffusion area and the second floating diffusion area;

The second switch unit includes m second switches, the first ends of the second switches are respectively connected to the second ends of the second transfer transistors, and the two second ends of the second switches are respectively connected to The first floating diffusion area is connected to the second floating diffusion area.
The image sensor according to claim 8, wherein the first pixel circuit and the second pixel circuit are further configured with a first transfer control line and a second transfer control line, wherein a plurality of the first transfer control lines The input ends are respectively connected to each of the first switches and each of the second switches, the output ends of the first transfer control lines are connected to the first floating diffusion region, and the plurality of second transfer control lines The input ends are respectively connected to the first switches and the second switches, and the output ends of the second transfer control lines are connected to the second floating diffusion region.
The image sensor according to claim 7, wherein the subunits are 16 pixels in 4 rows and 4 columns, arranged in the following manner:

Among them, W represents a panchromatic pixel, and A represents a color pixel.
The image sensor according to any one of claims 1-10, wherein the combined output mode comprises an addition mode, wherein,

The adding mode is: readout after performing analog-to-digital conversion on the total charge accumulated in the corresponding floating diffusion region by at least two pixels with the same color in the same subunit.
The image sensor according to claim 11, wherein the addition mode is: read after analog-to-digital conversion of the total charge accumulated in the corresponding floating diffusion area by all pixels of the same color in the same subunit out.
The image sensor according to claim 5, wherein the conversion circuit further comprises a third switch unit, a first end of the third switch unit is connected to an output end of one of the analog-to-digital converters, and the first end of the third switch unit is The second end of the three switch units is connected to the output end of another one of the analog-to-digital converters.
The image sensor according to claim 12, wherein the combined output mode further comprises a digital average mode or a first hybrid mode, wherein,

The digital averaging mode is: respectively performing analog-to-digital conversion on the charges generated by two pixels with the same color in the same subunit in time-sharing, and reading out after averaging the converted digital signals;

The first mixing mode is: the first digital signal output after analog-to-digital conversion of the first analog signal accumulated by the first part of pixels in the same subunit in the floating diffusion area, and the first digital signal output in the same subunit The second analog signal accumulated by the second part of pixels in the floating diffusion area is converted to an analog-to-digital conversion and then output as a second digital signal for averaging and then read out; wherein the first part of pixels and the second part of pixels have the same color, and The total number of pixels of all the partial pixels is equal to the total number of the color pixels or the panchromatic pixels.
The image sensor according to claim 5 or 13, wherein the conversion circuit further comprises:

A fourth switch unit, the first end of the fourth switch unit is connected to the readout circuit of the first pixel circuit, and the second end of the fourth switch unit is connected to the readout circuit of the second pixel circuit , for selectively turning on or off the average path between the two readout circuits.
The image sensor of claim 15, wherein the readout circuit comprises:

A reset transistor, the first end of the reset transistor is connected to the corresponding floating diffusion region, the second end of the reset transistor is used to receive a reset voltage, the control end of the reset transistor is used to receive a reset control signal, and resetting the floating diffusion region according to the reset control signal;

an amplifying transistor, the control terminal of the amplifying transistor is connected to the floating diffusion region, the first terminal of the amplifying transistor is connected to the second terminal of the reset transistor, and is used to amplify the charge in the floating diffusion region;

A selection transistor, the first end of the selection transistor is connected to the second end of the amplification transistor, the second end of the selection transistor is connected to the corresponding column control line, and the control end of the selection transistor is used to receive selection control signal, for outputting the amplified charge to the column control line according to the selection control signal; wherein,

The first end of the fourth switch unit is connected to the first end of the selection transistor in the first pixel circuit, and the second end of the fourth switch unit is connected to the first end of the selection transistor in the second pixel circuit. The first terminal of the selection transistor is connected.
The image sensor according to claim 15, wherein when the image sensor includes a third switching unit, the combined output mode further includes an analog average mode, a second mixed mode, and a third mixed mode, wherein,

The analog average mode is: average the charge numbers corresponding to two analog signals generated by two pixels with the same color in the same subunit in time-sharing, and read them out after analog-to-digital conversion;

The second mixing mode is: for the first analog signal accumulated in the floating diffusion area by the first part of pixels in the same subunit, and the accumulated first analog signal in the floating diffusion area of the second part of pixels in the same subunit The second analog signal is averaged and read out after analog-to-digital conversion; wherein the colors of the first part of pixels and the second part of pixels are the same, and the total number of pixels of all part of the pixels is the same as that of the color pixels or the full-color The total number of pixels is equal;

The third mixing mode is: for the first analog signal accumulated in the floating diffusion area by the first sub-part of pixels in the same sub-unit, and the second sub-part of the pixels in the same sub-unit in the floating diffusion The second analog signal accumulated in the area is averaged, and the first digital signal is output through analog-to-digital conversion; the third analog signal accumulated in the floating diffusion area by the third sub-part pixels in the same sub-unit, and the same sub-unit averaging the fourth analog signal accumulated in the floating diffusion area by the fourth sub-part of the pixels in the unit, outputting the second digital signal through analog-to-digital conversion, and averaging the first digital signal and the second digital signal Read; Wherein the color of the first sub-part pixel, the second sub-part pixel, the third sub-part pixel, and the fourth sub-part pixel is the same, and the total number of pixels of all sub-part pixels is equal to the total number of pixels of the sub-part pixel The total number of the color pixels or the panchromatic pixels in the subunits is equal.
The image sensor according to claim 1, wherein the two-dimensional pixel array includes a plurality of minimum repeating units, the minimum repeating units are 8 rows and 8 columns and 64 pixels, arranged in the following manner:

Among them, W represents a panchromatic pixel, and A, B, and C represent color pixels.
A camera assembly, comprising:

lens; and

The image sensor according to any one of claims 1-18, wherein the image sensor is capable of receiving light passing through the lens.
A mobile terminal, comprising:

casing; and

The camera assembly of claim 19, said camera assembly being combined with said housing.