CN110650301A - Image sensor, imaging method and device - Google Patents

Abstract

The embodiments of the present application disclose an image sensor and an imaging method and device, wherein the image sensor includes: a color filter array, an N-layer pixel array and a readout circuit, N is greater than 1 and less than the number of color light components of a color model; wherein the color filter array is arranged on the N-layer pixel array to allow light of the color light components of the color model to penetrate; at least one layer of the pixel array in the N-layer pixel array is used to convert light of at least two different color light components into photogenerated charges, and the at least two do not include the N types; the readout circuit is used to convert the photogenerated charges into electrical signals and output the electrical signals to form an image.

Description

Image sensor, imaging method and device

technical field

The embodiments of the present application relate to electronic technologies, and relate to, but are not limited to, image sensors, imaging methods, and devices.

Background technique

Foveon X3 is the world's first image sensor that can capture all colors in one pixel. Usually a digital camera using a Charge Coupled Device (CCD) or a Complementary Metal Oxide Semiconductor (CMOS) can only record the color model of Red Green Blue (RGB) on one pixel. ) model, one of the three color light components, namely red light, green light or blue light; while the Foveon X3 adopts three layers of photoelectric conversion elements, each layer records one of the color light components of RGB. In this way, the three photosensitive layers of the Foveon X3 capture RGB color light at different depths, so that 100% of the RGB color light can be captured, which can provide sharper images and better colors.

However, the Foveon X3 encountered a series of problems such as high power consumption and serious heat generation during work.

SUMMARY OF THE INVENTION

In view of this, embodiments of the present application provide an image sensor, an imaging method, and an apparatus. The technical solutions of the embodiments of the present application are implemented as follows:

In a first aspect, embodiments of the present application provide an image sensor, including: a color filter array, an N-layer pixel array, and a readout circuit, where N is greater than 1 and less than the number of color light components of a color model; wherein, the color filter array , which is arranged above the N-layer pixel array to allow light penetration of the color light components of the color model; at least one layer of pixel arrays in the N-layer pixel array is used to combine at least two different The light of the color light component is converted into photo-generated charges, and the at least two types do not include the N kinds; the readout circuit is used to convert the photo-generated charges into electrical signals, and output the electrical signals to form an image .

In a second aspect, an embodiment of the present application provides an imaging method, including: turning on an image sensor; transmitting light of a color light component of a color model through a color filter array of the image sensor;

Through at least one pixel array in the N-layer pixel array of the image sensor, the light of at least two different color light components is converted into photo-generated charges, N is greater than 1 and less than the number of color light components of the color model, so The at least two types do not include the N types; the photo-generated charges are converted into electrical signals through a readout circuit of the image sensor, and the electrical signals are output to form an image.

In a third aspect, embodiments of the present application provide an electronic device, including a memory, a processor, and the image sensor described in the embodiments of the present application, where the memory stores a computer program that can be run on the processor, and the processor executes The program implements the steps in the imaging method described in the embodiments of the present application.

In the embodiment of the present application, the image sensor includes: a color filter array, an N-layer pixel array, and a readout circuit, where N is greater than 1 and less than the number of color light components of the color model; wherein, at least one layer of pixels in the N-layer pixel array The array is used to convert the light of at least two different color light components into photo-generated charges; in this way, in the case of obtaining better image quality through fewer pixel arrays, the power consumption and generation of the image sensor during operation are reduced. of heat.

Description of drawings

FIG. 1 is a schematic structural diagram of an image sensor according to an embodiment of the present application;

FIG. 2 is a schematic structural diagram of another image sensor according to an embodiment of the present application;

3A is a schematic structural diagram of another image sensor according to an embodiment of the present application;

3B is a schematic cross-sectional view of a first-layer pixel array according to an embodiment of the present application;

4 is a schematic diagram of a misaligned stacking of a third pixel unit and a pixel unit of a first-layer pixel array according to an embodiment of the present application;

FIG. 5 is another schematic diagram of the dislocation stacking of the third pixel unit and the pixel unit of the first-layer pixel array according to the embodiment of the present application;

Figure 6 is a schematic diagram of the working principle of Foveon X3;

FIG. 7 is a schematic structural diagram of still another image sensor according to an embodiment of the present application;

8 is a schematic structural diagram of a color filter array according to an embodiment of the present application;

9 is a schematic cross-sectional view of each layer of pixel arrays according to an embodiment of the present application;

10 is a schematic structural diagram of a readout circuit according to an embodiment of the present application;

FIG. 11 is a schematic diagram of an implementation flowchart of an imaging method according to an embodiment of the present application;

FIG. 12 is a schematic diagram of a hardware entity of an electronic device according to an embodiment of the present application.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present application more clear, the specific technical solutions of the present application will be described in further detail below with reference to the accompanying drawings in the embodiments of the present application. The following examples are used to illustrate the present application, but are not intended to limit the scope of the present application.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of the present application, and are not intended to limit the present application.

In the following description, reference is made to "some embodiments" which describe a subset of all possible embodiments, but it is understood that "some embodiments" can be the same or a different subset of all possible embodiments, and Can be combined with each other without conflict.

It should be pointed out that the term "first\second\third" involved in the embodiments of the present application is only to distinguish similar objects, and does not represent a specific ordering of objects. It is understandable that "first\second\third" "Where permitted, the specific order or sequence may be interchanged to enable the embodiments of the application described herein to be practiced in sequences other than those illustrated or described herein.

An embodiment of the present application provides an image sensor. FIG. 1 is a schematic structural diagram of an image sensor according to an embodiment of the present application. As shown in FIG. 1 , the image sensor 10 includes: N-layer pixel arrays 101 to 10N, a color filter array 111 and a readout In circuit 121, N is greater than 1 and less than the number of color light components of the color model; wherein,

Taking the transmission direction of the light as a reference direction, the color filter array 111 is disposed on the N-layer pixel arrays 101 to 10N for allowing the light of the color light component of the color model to penetrate.

In this embodiment of the present application, the types of color models can be various, for example, the color model can be an RGB model, a CMYK model, or a Lab model, etc.; wherein, the RGB model has three color light components, namely red (R), Green (G) and blue (B), correspondingly, when implemented, the N-layer pixel array can be a two-layer pixel array, an exemplary structure can refer to the image sensor shown in FIG. 2 in the following embodiment; CMYK model With 4 color light components, namely cyan (Cyan, C), magenta (Magenta, M), yellow (Yellow, Y) and black (Black, K), correspondingly, when implemented, the N-layer pixel array can be two layers Pixel array or three-layer pixel array.

It can be understood that the function of the color filter of the color filter array is to filter the light of this color of the color filter. For example, for the RGB model, the color filter array may consist of a violet color filter for allowing blue and red light to pass through, and a yellow color filter for allowing green and red light to pass through. Red light penetrates. For another example, for the CMYK model, the color filter array can consist of a cyan filter that transmits cyan light, a magenta filter that transmits magenta light, a yellow filter that transmits yellow light, and a black filter that transmits black light. Color chip composition.

At least one pixel array of the N-layer pixel arrays 101 to 10N is used for converting at least two different light components of the color light into photo-generated charges, and the at least two types do not include the N types.

It should be noted that other pixel arrays in the N-layer pixel array except the at least one layer of pixel array are used to convert the light of at least one of the color light components into photo-generated charges. For example, assuming that N is 2, one layer of pixel array is used to convert light of two different color light components into photo-generated charges, and the other layer of pixel array is used to convert light of the other one or two color light components into photo-generated charges.

The readout circuit 121 is used for converting the photo-generated charges into electrical signals and outputting the electrical signals to form an image.

In the embodiment of the present application, the image sensor includes: a color filter array, an N-layer pixel array, and a readout circuit, where N is greater than 1 and less than the number of color light components of the color model; wherein, at least one layer in the N-layer pixel array The pixel array is used to convert the light of at least two different color light components into photo-generated charges; in this way, in the case of obtaining better image quality through fewer pixel arrays, the power consumption of the image sensor during operation is reduced and the In addition, since the number of pixel array layers of the image sensor is smaller than the number of color light components of the color model, this will reduce the difficulty of manufacturing the image sensor. For example, for the RGB model, N is 2, that is, the image sensor has a two-layer pixel array, which is less difficult to process than the Foveon X with a three-layer pixel array.

An embodiment of the present application further provides an image sensor. FIG. 2 is a schematic structural diagram of an image sensor according to an embodiment of the present application. As shown in FIG. 2 , the image sensor 20 includes: a first layer pixel array 201 and a second layer pixel array 202 , a filter Color chip array 203 and readout circuit 204; wherein,

Taking the transmission direction of the light as a reference direction, the color filter array 203 is disposed on the first layer of the pixel array 201 for allowing the light of the color light component of the RGB color model to penetrate.

It should be noted that the first layer of pixel arrays refers to the layer of pixel arrays that the light reaches first. As shown in FIG. 2 , with the direction of light transmission as the reference direction, the first layer of pixel arrays 201 is stacked on the second layer of pixel arrays 201 . Above the layer pixel array 202 , the color filter array 203 is stacked on the first layer pixel array 201 .

The first-layer pixel array 201 is disposed between the color filter array 203 and the second-layer pixel array 202, and is used for converting the light of the two different color components into photo-generated charges.

Here, the two different color light components may be any two components among the three color light components of red light, green light and blue light in the RGB model. For example, it can be blue light and green light. Correspondingly, the second layer of pixel array is used to absorb red light (that is, convert red light into photo-generated charges); for another example, the two different color light components can also be red light and Green light, the second layer of pixel array is used to absorb blue light.

It should be noted that, in other embodiments, the first layer of pixel array 201 can also be used to convert light of only one color light component into photo-generated charges, while the second layer of pixel array 202 is used to convert the remaining two different color lights The components of light are converted into photogenerated charges. For example, the first-layer pixel array 201 is used for converting red light into photo-generated charges, and the second-layer pixel array 202 is used for converting blue light and green light into photo-generated charges. For another example, the first-layer pixel array 201 is used for converting green light into photo-generated charges, and the second-layer pixel array 202 is used for converting blue light and red light into photo-generated charges. That is to say, the first-layer pixel array 201 can be used to convert light of any color light component in the RGB model into photo-generated charges.

It should also be noted that, for a color model with four color light components (such as the CMYK model), the pixel array combination of the image sensor can be any of the following:

The first is: including two layers of pixel arrays, wherein the first layer of pixel arrays can be used to convert light of one, two or three different color components of the color model into photo-generated charges, and the second layer of pixel arrays are used for Converts light from the remaining color components of the color model to photogenerated charges. Taking the CMYK model as an example, the first layer of pixel array can be used to absorb cyan and magenta light, and the second layer of pixel array can be used to absorb yellow and black light.

The second is: including a three-layer pixel array, any of which can be used to convert the light of two different color components of the color model into photo-generated charges, and the other two layers of pixel arrays are used to convert the rest of the color model. One color component of light is converted into photogenerated charges. Taking the CMYK model as an example, the first layer of pixel array can be used to absorb cyan light, magenta light and yellow light, and the second layer of pixel array can be used to absorb black light.

The second layer of pixel array 202 is used to convert the light of the other color components of the color model into photo-generated charges.

The readout circuit 204 is used for converting the photo-generated charges into electrical signals and outputting the electrical signals to form an image.

In the embodiment of the present application, the image sensor using the RGB model has a two-layer pixel array. Compared with the Foveon X having a three-layer pixel array, the number of pixel units is greatly reduced, which makes the electrical signal output by the readout circuit The amount of data is reduced, which can reduce the complexity of the RGB restoration algorithm, improve the color accuracy, and provide conditions for obtaining a higher frame rate.

An embodiment of the present application further provides an image sensor. FIG. 3A is a schematic structural diagram of an image sensor according to an embodiment of the present application. As shown in FIG. 3A , the image sensor 30 includes: a first-layer pixel array 301 and a second-layer pixel array 302 , a filter Color chip array 303 and readout circuit 304; wherein,

The first-layer pixel array 301 is disposed between the color filter array 303 and the second-layer pixel array 302, and includes M first pixel units 3011 and L second pixel units 3012, where M and L are both integers greater than 0 .

During implementation, the first pixel units 3011 and the second pixel units 3012 are alternately arranged, and M may be equal to L. The arrangement may be the manner shown in FIG. 3B , or may be other arrangements.

The second-layer pixel array 302 includes K third pixel units 3021 , where K is an integer greater than 0.

It can be understood that the first pixel unit, the second pixel unit and the third pixel unit are three different pixel units, and different pixel units absorb light of different wavelengths correspondingly. For example, the first pixel unit is used to absorb blue light with wavelengths between 407 nanometers (nm) and 505 nm, the second pixel unit is used to absorb green light with wavelengths between 505 nm and 525 nm, and the third pixel unit is used to absorb Red light with wavelengths between 640nm and 780nm.

Taking the transmission direction of the light as the reference direction, the color filter array 303 is arranged above the pixel array 301 of the first layer, and includes M first color filters 3031 and the L second color filters 3032. The color filter 3031 is aligned and stacked with the first pixel unit 3011 , and the second color filter 3032 is aligned and stacked with the second pixel unit 3012 .

The first color filter 3031 is used to allow the light of the color light component corresponding to the first pixel unit 3011 and the light of the color light component corresponding to the third pixel unit 3021 to penetrate.

The second color filter 3032 is used for allowing the light of the color light component corresponding to the second pixel unit 3012 and the light of the color light component corresponding to the third pixel unit 3021 to penetrate.

It can be understood that since the wavelengths of light absorbed by the above three pixel units are different, the color filters stacked above the pixel units are also different accordingly. For example, if the first pixel unit is used to absorb blue light, the first color filter is a purple color filter, and the second pixel unit is used to absorb green light, so the second color filter is a yellow color filter, so that the purple color filter The color filter filters out blue light and red light, wherein the blue light is absorbed by the first pixel unit, the red light is absorbed by the third pixel unit, the yellow color filter filters out green light and red light, the green light is absorbed by the first pixel unit, and the red light is absorbed by the first pixel unit. The light is absorbed by the third pixel unit; for another example, if the first pixel unit is used to absorb red light, the first color filter is a magenta color filter, and the second pixel unit is used to absorb blue light, then the second color filter is The cyan filter, in this way, the magenta filter filters out red and green light, the red light is absorbed by the first pixel unit, the green light is absorbed by the third pixel unit, the cyan filter filters out blue and green light, and the blue light is Absorbed by the second pixel unit, green light is absorbed by the third pixel unit.

In this embodiment, both color filters can transmit the light absorbed by the pixel units of the second layer pixel array, so even if the number of the second layer pixel units is small, the image quality will not be affected.

Each of the first pixel unit 3011 , the second pixel unit 3012 and the third pixel unit 3021 is respectively used for converting the light of its corresponding color component into the photo-generated charges.

It can be understood that the wavelengths of light absorbed by different types of pixel units are different. For example, the first pixel unit is used to absorb blue light, the second pixel unit is used to absorb red light, and the third pixel unit is used to absorb green light. This is because the photoelectric conversion elements included in the three different pixel units are different. For example, as shown in Table 1, the diameter of the photosensitive region of the cylindrical photodiode (PhotoDiode, PD) included in the first pixel unit for absorbing blue light is 60 nm, and the cylindrical photodiode in the second pixel unit for absorbing red light has a diameter of 60 nm. The diameter of the photosensitive region is 120 nm, and the diameter of the photosensitive region of the cylindrical photodiode of the third pixel unit for absorbing green light is 90 nm.

Table 1

pixel unit color component The diameter of the photosensitive area of the photodiode first pixel unit Blu-ray 60nm second pixel unit red light 120nm third pixel unit green light 90nm

The readout circuit 304 is used for converting the photo-generated charges into electrical signals and outputting the electrical signals to form an image.

In the embodiment of the present application, the image sensor using the RGB model has two layers of pixel arrays, wherein the first layer of pixel arrays has two types of pixel units, and the second layer of pixel arrays has one kind of pixel units. In this way, compared with the first layer of pixel arrays The pixel array has one type of pixel unit, and the second-layer pixel array has two types of pixel units. The wiring is performed between the gaps of the second-layer pixel array. Therefore, the former is simpler to implement metal wire wiring, which greatly reduces the cost of wiring. Process difficulty.

In other embodiments, each of the pixel units includes a plurality of photoelectric conversion elements 305; wherein, the diameter of the photosensitive region of each photoelectric conversion element is smaller than the wavelength of light of its corresponding color light component, so as to convert its corresponding color light component The light is converted into the photogenerated charge.

It should be noted that the diameter of the photosensitive area refers to the distance from the center of the photosensitive area to two points on the side. For example, for example, if the photoelectric conversion element is a cylindrical photodiode, its photosensitive area is circular, and the diameter of the photosensitive area is the diameter of the circle; for another example, if the photoelectric conversion element is a square photodiode, its photosensitive area is square, and the photosensitive area is square. The diameter of the area is the length of the diagonal or side of the square.

It can be understood that, in this embodiment, the diameter of the photosensitive region of the photoelectric conversion element is smaller than the wavelength of the light of its corresponding color light component, so that the incident light can be optically resonated in the cavity of the photoelectric conversion element, thereby enhancing the photoelectricity. Convert the optical density of states of the element, increase the quantum efficiency, and improve the image quality.

For example, when the diameter of the photosensitive region of a cylindrical photodiode is 60 nm, it can absorb more than 95% of blue light; when the diameter of the photosensitive region of a cylindrical photodiode is 90 nm, it can absorb more than 90% of green light.

In implementation, the number of photoelectric conversion elements of the three diameters may be the same, or of course may be different. However, the distance between adjacent photoelectric conversion elements is at least 50 nm, which can reduce crosstalk. The thickness of the photosensitive region is generally between 80nm and 500nm, and the longer the thickness, the higher the light absorption rate.

In other embodiments, the number of pixel units of the pixel array 302 of the second layer is smaller than the number of pixel units of the pixel array 301 of the first layer.

For example, the number of pixel units of the pixel array 302 of the second layer may be 3/4 or 1/2 of the number of pixel units of the pixel array 301 of the first layer. Of course, the number of pixel units of the second-layer pixel array 302 can also be equal to the number of pixel units of the first-layer pixel array 301, but in this way, the power consumption of the image sensor during operation will increase, and correspondingly, the heat generated will also increase.

In the case where the number of pixel units of the second layer pixel array 302 is smaller than the number of pixel units of the first layer pixel array 301, as shown in FIG. 4, the third pixel unit 3021, the first pixel unit 3011 and the second pixel unit 3012 can be Misaligned stacking.

It should be noted that there are many ways of staggered stacking, for example, the third pixel unit and the pixel unit of the first layer of pixel arrays are offset by one or more photoelectric conversion elements; for another example, the number of the third pixel unit is the same as that of the first layer When the number of pixel units of the pixel array is half, as shown in FIG. 5 , the third pixel unit 3021 is arranged at the center position below the four pixel units of the pixel array of the first layer.

The main working principle of Foveon X3, as shown in Figure 6, uses the difference in the absorption length of light of different wavelengths in silicon to measure the signals obtained at different depths, and finally realizes the detection of three RGB colors in one pixel.

However, Foveon X3 has high power consumption, serious heat generation, large pixel size, large data volume, low frame rate, spectral crosstalk (crosstalk) may be serious, the algorithm for restoring RGB is complex, the color is inaccurate, and the color performance is poor under high light sensitivity. , the sensitivity (ISO) is less than or equal to 100, and the color noise is high in low light.

Based on this, an exemplary application of the embodiments of the present application in a practical application scenario will be described below.

An embodiment of the present application provides a subwavelength photodiode-based dual-layer complementary metal-oxide-semiconductor image sensor (CMOS Image Sensor, CIS). As shown in FIG. 7 , the image sensor 70 specifically includes: two layers of pixels, and the first layer is composed of two types of pixels. One pixel is covered with a purple color filter 701, and below the color filter 701 are several cylindrical photodiodes 702 with a diameter of 60 nm, which are used to absorb blue light; the other pixel is covered with a yellow color filter 703, and below the color filter 703 is a Several cylindrical photodiodes 704 with a diameter of 90 nm are used to absorb green light. The second layer of pixels consists of several cylindrical photodiodes 705 with a diameter of 120 nm for absorbing red light. When implemented, the number of photodiodes for the three diameters is the same. The number of pixels in the second layer is half that of the first layer, and is located between four pixels in the first layer.

In this way, the signal-to-noise ratio of the CIS and the resolving power of the CIS can be improved by means of pixel stacking, and the false color in the demosaicing process can be reduced.

As shown in Figure 8, the pixel photodiode is covered with a layer of color filters, including a purple color filter P that can absorb green light and transmit blue light and red light, and a yellow color filter Y that can absorb blue light and transmit green light and red light. , the purple filter P and the yellow filter Y are arranged alternately.

Based on the CIS structure of the stacked pixel shown in Figure 7, its working method is as follows: after the light passes through the color filter P(Y), first the blue light (green light) passes through several cylindrical photodiode arrays. Resonance absorption, more than 95% of blue light (more than 90% of green light) will be absorbed, and converted into electrical signals stored in the first layer of PD, read out the signal of the B (G) channel, almost no red light absorption. When the light reaches the second layer of PD, the red light will be absorbed by several cylindrical photodiodes in the second layer (the diameter of the cylindrical photodiode is about 120nm).

It should be noted that the diameter of the cylindrical photodiode covered by the color filter P is about 60 nm, the diameter of the cylindrical photodiode covered by the color filter Y is about 90 nm, and the thickness of the photosensitive region of the photodiode is between 80 nm and 500 nm. , the longer the thickness, the higher the absorption rate of light.

As shown in Figure 9, the left figure is a schematic cross-sectional view of the first layer of photodiodes, mainly photodiodes 901 for absorbing blue light (referred to as blue photodiodes) and photodiodes 902 for absorbing green light (abbreviated as photodiodes). Green photodiode), the second layer is a photodiode 903 for absorbing red light and a circuit 904 that connects the blue and green photodiodes to the transfer gates. The number of cylindrical photodiodes is determined by the pixel size, and it is necessary to ensure that the spacing between adjacent cylindrical photodiodes is greater than 50 nm.

Similar to the readout circuit of the conventional pixel structure, the readout circuit of the stacked CIS pixel is shown in FIG. 10 . The workflow is as follows: Step 1. Exposure: The electron-hole pairs generated by light irradiation will be separated due to the presence of the PPD electric field, the electrons move to the n region, and the holes move to the p region; Step 2, Reset: At the end of the exposure, Activate RST to reset the readout area to a high level; step 3, read out the reset level: after the reset is completed, read out the reset level, and store the readout signal in the first capacitor; step 4, charge transfer : Activate the TX to completely transfer the charge from the photosensitive area to the n+ area for readout; Step 5, read out the signal level. It should be noted that each layer of photodiodes has such a readout circuit.

In the embodiments of the present application, based on subwavelength photodiodes and using stacked pixels, compared with the CIS of the Bayer array, the false color of the demosaicing process is reduced, and the resolution of the CIS is improved; In terms of pixels, power consumption is reduced, and the number of pixels in the second layer of the CIS structure provided by the embodiments of the present application is reduced, so that power consumption can be further reduced.

In other embodiments, cylindrical photodiodes may be replaced with regular polygonal photodiodes.

In other embodiments, the red and green photodiodes can be appropriately thickened to increase the absorption of both types of light.

In other embodiments, the three colors of R, G, and B can be changed arbitrarily, but it should be noted that the color filters also need to be changed accordingly.

Based on the foregoing embodiments, an embodiment of the present application provides an imaging method. FIG. 11 is a schematic flowchart of the implementation of the imaging method according to the embodiment of the present application. As shown in FIG. 11 , the method may at least include the following steps 111 to 114:

Step 111, turn on the image sensor;

Step 112, transmit the light of the color light component of the color model through the color filter array of the image sensor;

Step 113: Convert at least two different light components of the color light into photo-generated charges through at least one pixel array in the N-layer pixel array of the image sensor, and the at least two types do not include the N types, N is greater than 1 and less than the number of chromatic components of the color model;

Step 114 , converting the photo-generated charges into electrical signals through a readout circuit of the image sensor, and outputting the electrical signals to form an image.

In other embodiments, converting the light of at least two different color light components into photo-generated charges through at least one pixel array in the N-layer pixel array of the image sensor includes: in the N-layer pixel array The pixel array includes a first layer of pixel arrays and a second layer of pixel arrays, and when the first layer of pixel arrays is disposed between the color filter array and the second layer of pixel arrays, through the first layer of pixel arrays The layer pixel array converts the light of the two different color light components into photo-generated charges.

In other embodiments, the converting light of two different color light components into photo-generated charges through the first layer of pixel arrays includes: passing through M first pixel units of the first layer of pixel arrays and the L second pixel units convert the light of their corresponding color light components into the photo-generated charges.

In other embodiments, the method further includes: converting the light of the color light component corresponding to itself into the photo-generated charge through the K third pixel units of the second-layer pixel array.

In other embodiments, the converting the light of the color light component corresponding to itself into the photo-generated charge through the M first pixel units and the L second pixel units of the pixel array of the first layer includes: passing through each The photoelectric conversion element of the pixel unit converts the light of its corresponding color light component into the photo-generated charge, and each photoelectric conversion element has a photosensitive area whose diameter is smaller than the light wavelength of its corresponding color light component.

In other embodiments, the transmitting light of a color light component of a color model through a color filter array of the image sensor includes: transmitting the M first color filters in the color filter array. The light of the color light component corresponding to the first pixel unit and the light of the color light component corresponding to the third pixel unit are transmitted through the L second color filters in the color filter array corresponding to the second pixel unit. The light of the color light component and the light of the color light component corresponding to the third pixel unit; wherein, the first color filter is aligned and stacked with the first pixel unit, and the second color filter is aligned with the second color filter. Pixel cells are aligned and stacked.

The descriptions of the above method embodiments are similar to the descriptions of the above image sensor embodiments, and have similar beneficial effects to the image sensor embodiments. For technical details not disclosed in the method embodiments of the present application, please refer to the description of the image sensor embodiments of the present application for understanding.

It should be noted that, in the embodiments of the present application, when the image sensor is sold or used as an independent product, it may also be stored in a computer-readable storage medium. In addition, if the above-mentioned imaging method is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present application may be embodied in the form of software products in essence or the parts that contribute to related technologies. The computer software products are stored in a storage medium and include several instructions to make An electronic device (which may be a mobile phone, a tablet computer, a notebook computer, a desktop computer, a robot, a drone, etc.) executes all or part of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a removable hard disk, a read only memory (Read Only Memory, ROM), a magnetic disk or an optical disk and other mediums that can store program codes. As such, the embodiments of the present application are not limited to any specific combination of hardware and software.

Correspondingly, an embodiment of the present application provides an electronic device, and FIG. 12 is a schematic diagram of a hardware entity of the electronic device according to the embodiment of the present application. As shown in FIG. 12 , the hardware entity of the electronic device 120 includes: a memory 1201 , a processor 1202 and an image sensor 1203, the memory 1201 stores a computer program that can run on the processor 1202, and the processor 1202 implements the steps in the imaging method provided in the above embodiment when the program is executed.

The memory 1201 is configured to store instructions and applications executable by the processor 1202, and can also cache data to be processed or processed by the processor 1202 and each module in the electronic device 120 (for example, image data, audio data, voice communication data and video communication data), which can be implemented by flash memory (FLASH) or random access memory (Random Access Memory, RAM).

Correspondingly, the embodiments of the present application provide a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, implements the steps in the imaging method provided in the foregoing embodiments.

It should be pointed out here that the descriptions of the above storage medium and device embodiments are similar to the descriptions of the above method embodiments, and have similar beneficial effects to the method embodiments. For technical details not disclosed in the embodiments of the storage medium and device of the present application, please refer to the description of the method embodiments or the image sensor embodiments of the present application to understand.

It is to be understood that reference throughout the specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic associated with the embodiment is included in at least one embodiment of the present application. Thus, appearances of "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily necessarily referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments. It should be understood that, in various embodiments of the present application, the size of the sequence numbers of the above-mentioned processes does not mean the sequence of execution, and the execution sequence of each process should be determined by its functions and internal logic, and should not be dealt with in the embodiments of the present application. implementation constitutes any limitation. The above-mentioned serial numbers of the embodiments of the present application are only for description, and do not represent the advantages or disadvantages of the embodiments.

It should be noted that, herein, the terms "comprising", "comprising" or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements, It also includes other elements not expressly listed or inherent to such a process, method, article or apparatus. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element.

In the several embodiments provided in this application, it should be understood that the disclosed image sensor, device and method may be implemented in other manners. The device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined, or Can be integrated into another system, or some features can be ignored, or not implemented. In addition, the coupling, or direct coupling, or communication connection between the components shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be electrical, mechanical or other forms. of.

The unit described above as a separate component may or may not be physically separated, and the component displayed as a unit may or may not be a physical unit; it may be located in one place or distributed to multiple network units; Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

In addition, each functional unit in each embodiment of the present application may all be integrated into one processing unit, or each unit may be separately used as a unit, or two or more units may be integrated into one unit; the above integration The unit can be implemented either in the form of hardware or in the form of hardware plus software functional units.

Those of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by program instructions related to hardware, the aforementioned program can be stored in a computer-readable storage medium, and when the program is executed, the execution includes: The steps of the above method embodiments; and the aforementioned storage medium includes: a removable storage device, a read only memory (Read Only Memory, ROM), a magnetic disk or an optical disk and other media that can store program codes.

Alternatively, if the above-mentioned integrated units of the present application are implemented in the form of software function modules and sold or used as independent products, they may also be stored in a computer-readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present application may be embodied in the form of software products in essence or the parts that contribute to related technologies. The computer software products are stored in a storage medium and include several instructions to make An electronic device (which may be a mobile phone, a tablet computer, a notebook computer, a desktop computer, a robot, a drone, etc.) executes all or part of the methods described in the various embodiments of the present application. The aforementioned storage medium includes various media that can store program codes, such as a removable storage device, a ROM, a magnetic disk, or an optical disk.

The methods disclosed in the several image sensor embodiments provided in this application can be combined arbitrarily without conflict to obtain a new image sensor embodiment.

The features disclosed in the several product embodiments provided in this application can be combined arbitrarily without conflict to obtain a new product embodiment.

The features disclosed in several method or device embodiments provided in this application may be combined arbitrarily under the condition of no conflict to obtain new method embodiments or device embodiments.

The above is only the embodiment of the present application, but the protection scope of the present application is not limited to this. Covered within the scope of protection of this application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims (10)

1. An image sensor, characterized in that the image sensor comprises: a color filter array, an N-layer pixel array and a readout circuit, where N is greater than 1 and less than the number of color light components of a color model; wherein, the color filter array, disposed above the N-layer pixel array, for allowing light penetration of the color light components of the color model; At least one layer of pixel arrays in the N-layer pixel array is used to convert at least two different light components of the color light into photo-generated charges, the at least two types not including the N types; The readout circuit is used for converting the photo-generated charges into electrical signals and outputting the electrical signals to form an image. 2. The image sensor according to claim 1, wherein the color model is an RGB model, correspondingly, The N-layer pixel array includes a first-layer pixel array and a second-layer pixel array, and the first-layer pixel array is disposed between the color filter array and the second-layer pixel array. 3. The image sensor according to claim 2, wherein the pixel array of the first layer comprises M first pixel units and L second pixel units, and the pixel array of the second layer comprises K third pixel units Pixel unit, M, L and K are all integers greater than 0; among them, Each of the first pixel unit, the second pixel unit, and the third pixel unit is respectively used for converting the light of its corresponding color light component into the photo-generated charge. 4. The image sensor according to claim 3, wherein each of the pixel units comprises a plurality of photoelectric conversion elements; wherein, Each of the photoelectric conversion elements has a photosensitive region with a diameter smaller than the wavelength of the light of the corresponding color component, so as to convert the light of the corresponding color component into the photo-generated charge. 5. The image sensor according to claim 3, wherein the color filter array comprises the M first color filters and the L second color filters, the first color filters Aligned and stacked with the first pixel unit, the second color filter is aligned and stacked with the second pixel unit; wherein, The first color filter is used to allow the light of the color light component corresponding to the first pixel unit and the light of the color light component corresponding to the third pixel unit to penetrate; The second color filter is used for allowing the light of the color light component corresponding to the second pixel unit and the light of the color light component corresponding to the third pixel unit to penetrate. 6 . The image sensor according to claim 3 , wherein the number of pixel units of the pixel array of the second layer is smaller than the number of pixel units of the pixel array of the first layer. 7 . 7 . The image sensor according to claim 6 , wherein the third pixel unit is stacked with the first pixel unit and the second pixel unit in dislocation. 8 . 8. An imaging method, characterized in that the method comprises: Turn on the image sensor; The light of the color light component of the color model is transmitted through the color filter array of the image sensor; Through at least one pixel array in the N-layer pixel array of the image sensor, at least two kinds of light of the color light components are converted into photo-generated charges, the at least two kinds do not include the N kinds, and N is greater than 1 and less than the number of chromatic components of the color model; The photo-generated charges are converted into electrical signals by a readout circuit of the image sensor, and the electrical signals are output to form an image. 9 . The method according to claim 8 , wherein the at least one pixel array in the N-layer pixel array of the image sensor converts the light of at least two different color light components into photogenerated light. 10 . charge, including: In the case where the N-layer pixel array includes a first-layer pixel array and a second-layer pixel array, and the first-layer pixel array is disposed between the color filter array and the second-layer pixel array, Through the pixel array of the first layer, the light of the two different color light components is converted into photo-generated charges. 10. An electronic device comprising a memory, a processor and the image sensor according to any one of claims 1 to 7, wherein the memory stores a computer program that can be executed on the processor, wherein the processor The steps in the imaging method of claim 8 or 9 are carried out when the program is executed.

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