CN111182244A

CN111182244A - Image sensor and image processing apparatus

Info

Publication number: CN111182244A
Application number: CN202010023821.2A
Authority: CN
Inventors: 杨鑫
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2020-01-09
Filing date: 2020-01-09
Publication date: 2020-05-19

Abstract

An embodiment of the application discloses an image sensor and an image processing apparatus, the CIS includes: the pixel array comprises a light filtering unit, a pixel unit and a reading circuit, wherein the light filtering unit and the pixel unit are both equilateral triangles, the light filtering unit comprises a first color filter and a second color filter, and the pixel unit comprises a first pixel unit and a second pixel unit; the readout circuit is connected with the pixel unit; the first color filter is covered on the first pixel unit, and the second color filter is covered on the second pixel unit; the first pixel unit comprises a first sub-pixel and a second sub-pixel, wherein the first sub-pixel is stacked on the second sub-pixel; a first PD column is arranged in the first sub-pixel, a second PD column is arranged in the second sub-pixel, and a third PD column is arranged in the second pixel unit.

Description

Image sensor and image processing apparatus

Technical Field

The embodiment of the application relates to the field of image processing, in particular to an image sensor and an image processing device.

Background

An image sensor is a Device capable of converting an optical signal into an electrical signal, and may be classified into two types, a Charge Coupled Device (CCD) and a Complementary Metal-oxide semiconductor (CMOS). The CMOS Image Sensor (CIS) is compatible with a signal processing chip and other manufacturing processes, and therefore is easy to integrate a system on a chip, and meanwhile, compared with a charge coupled device Sensor, power consumption is superior, and an Image processing noise reduction algorithm can improve a signal-to-noise ratio, and therefore, the CIS has an advantage in the field of Image Sensor application.

Since image processing apparatuses using a CCD or a CMOS each record one color on the same pixel, for example, each pixel unit in a conventional CIS can only absorb one light signal of RGB, and thus there is a problem that the utilization rate of the light signal is low.

Usually, detection of R, G, B three colors by one pixel can be realized by increasing the pixel size and optimizing the algorithm, however, the method often has the problems of large pixel size, complex algorithm and the like, and still cannot solve the problem of low optical signal utilization rate, which results in the defect of poor color detection effect of the image sensor.

Disclosure of Invention

The embodiment of the application provides an image sensor and an image processing device, can improve the utilization ratio of optical signals, and the color restoration accuracy is high, has improved detection effect greatly.

The technical scheme of the embodiment of the application is realized as follows:

in a first aspect, an embodiment of the present application provides a CIS, including: the pixel array comprises a light filtering unit, a pixel unit and a reading circuit, wherein the light filtering unit and the pixel unit are both in an equilateral triangle shape, the light filtering unit comprises a first color filter and a second color filter, and the pixel unit comprises a first pixel unit and a second pixel unit;

the readout circuit is connected with the pixel unit;

the first color filter is covered on the first pixel unit, and the second color filter is covered on the second pixel unit;

the first pixel unit comprises a first sub-pixel and a second sub-pixel, wherein the first sub-pixel is stacked on the second sub-pixel;

a first PD pillar is arranged in the first sub-pixel, a second PD pillar is arranged in the second sub-pixel, and a third PD pillar is arranged in the second pixel unit.

In a second aspect, an embodiment of the present application provides an image processing apparatus including a CIS including a filter unit, a pixel unit, and a readout circuit, wherein the filter unit and the pixel unit are each an equilateral triangle, the filter unit includes a first color filter and a second color filter, and the pixel unit includes a first pixel unit and a second pixel unit; the readout circuit is connected with the pixel unit; the first color filter is covered on the first pixel unit, and the second color filter is covered on the second pixel unit; the first pixel unit comprises a first sub-pixel and a second sub-pixel, wherein the first sub-pixel is stacked on the second sub-pixel; a first PD pillar is arranged in the first sub-pixel, a second PD pillar is arranged in the second sub-pixel, and a third PD pillar is arranged in the second pixel unit.

The embodiment of the application provides an image sensor and an image processing device, wherein the image processing device is provided with a CIS, the CIS comprises a light filtering unit, a pixel unit and a reading circuit, the light filtering unit and the pixel unit are both equilateral triangles, the light filtering unit comprises a first color filter and a second color filter, and the pixel unit comprises a first pixel unit and a second pixel unit; the readout circuit is connected with the pixel unit; the first color filter is covered on the first pixel unit, and the second color filter is covered on the second pixel unit; the first pixel unit comprises a first sub-pixel and a second sub-pixel, wherein the first sub-pixel is stacked on the second sub-pixel; a first PD column is arranged in the first sub-pixel, a second PD column is arranged in the second sub-pixel, and a third PD column is arranged in the second pixel unit. That is, in the embodiment of the present application, a pixel unit in the CIS may include two sub-pixels vertically stacked, each sub-pixel has a PD pillar disposed therein for absorbing one color light, and in combination with a filter covering the pixel unit, a single pixel unit selectively absorbs different color lights of incident light at the same time. Therefore, in the application, the CIS can simultaneously acquire light signals of multiple colors through the first pixel unit absorbing the first color light and the second pixel unit absorbing the second color light and the second pixel unit absorbing the third color light, so that the utilization rate of the light signals can be improved, the signal-to-noise ratio of the CIS is improved, and the efficiency and the quality of image processing are improved.

Drawings

FIG. 1 is a schematic diagram of a CIS of the FSI type;

FIG. 2 is a schematic of a CIS of the BSI formula;

FIG. 3 is a schematic representation of a Bayer array;

FIG. 4 is a first schematic diagram of the CIS;

FIG. 5 is a schematic diagram of a CIS;

FIG. 6 is a top view of the pixel unit;

FIG. 7 is a first schematic diagram of a cross-section of a pixel cell;

FIG. 8 is a second schematic diagram of a cross-section of a pixel cell;

FIG. 9 is a schematic view of incident light absorption;

FIG. 10 is a first schematic diagram of a filter unit;

FIG. 11 is a second schematic diagram of a filter unit;

FIG. 12 is a third schematic view of a filter unit;

FIG. 13 is a schematic diagram of a CIS;

FIG. 14 is a diagram illustrating a CIS;

fig. 15 is a schematic structural diagram of an image processing apparatus according to an embodiment of the present disclosure.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant application and are not limiting of the application. It should be noted that, for the convenience of description, only the parts related to the related applications are shown in the drawings.

The CIS of the cmos image sensor may include two different structures of Front Side Illumination (FSI) and Back Side Illumination (BSI), where fig. 1 is a schematic diagram of the CIS of the FSI and fig. 2 is a schematic diagram of the CIS of the BSI, and as shown in fig. 1 and 2, the CIS of the cmos image sensor includes a semiconductor substrate, a Photodiode (PD), a red filter, a green filter, a blue filter, a pixel spacer, and a metal wiring layer. Wherein each filter is further provided with a lens.

For a conventional complementary metal oxide image sensor, both FSI and BSI, PDs in the conventional complementary metal oxide image sensor completely absorb light of 400 nm to 1100 nm, so that a filter needs to be arranged to control the absorption of one of RGB by the same pixel.

The most common color filter array configuration is the Bayer filter. The odd columns (or even columns) of the Bayer filter include interleaved red and green filters, while the even columns (or odd columns) thereof include interleaved green and blue filters. Since the human eye is sensitive to green light, the number of green filters is twice that of red or blue filters, and is therefore also called RGBG, GRGB or RGGB. Fig. 3 is a schematic view of a Bayer array, and as shown in fig. 3, 50% of the arrangement of color filters in Bayer filter is green G, 25% is red R, and the other 25% is blue B.

However, just as each pixel unit in the conventional cmos image sensor can only absorb one of RGB light signals, for example, R light signals are wasted, and therefore, the utilization rate of the light signals is low, thereby reducing the efficiency and quality of image processing.

In order to solve the problems in the prior art, in an embodiment of the present application, a CIS is provided in an image processing apparatus, the CIS includes a filter unit, a pixel unit, and a readout circuit, where the filter unit and the pixel unit are both equilateral triangles, the filter unit includes a first color filter and a second color filter, and the pixel unit includes a first pixel unit and a second pixel unit; the readout circuit is connected with the pixel unit; the first color filter is covered on the first pixel unit, and the second color filter is covered on the second pixel unit; the first pixel unit comprises a first sub-pixel and a second sub-pixel, wherein the first sub-pixel is stacked on the second sub-pixel; a first PD column is arranged in the first sub-pixel, a second PD column is arranged in the second sub-pixel, and a third PD column is arranged in the second pixel unit. That is, in the embodiment of the present application, a pixel unit in the CIS may include two sub-pixels vertically stacked, each sub-pixel has a PD pillar disposed therein for absorbing one color light, and in combination with a filter covering the pixel unit, a single pixel unit selectively absorbs different color lights of incident light at the same time. Therefore, in the application, the CIS can simultaneously acquire light signals of multiple colors through the first pixel unit absorbing the first color light and the second pixel unit absorbing the second color light and the second pixel unit absorbing the third color light, so that the utilization rate of the light signals can be improved, the signal-to-noise ratio of the CIS is improved, and the efficiency and the quality of image processing are improved.

The cmos image sensor CIS in the image processing apparatus proposed in the present application may be FSI or BSI, but the present application is not particularly limited thereto, and the following examples will describe BSI as an example.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

In an embodiment of the present disclosure, fig. 4 is a schematic structural diagram of a CIS, and as shown in fig. 4, in an embodiment of the present disclosure, the cmos image sensor 10 may include: a filter unit 11, a pixel unit 12, and a readout circuit 13. The filter unit 11 and the pixel unit 12 are all equilateral triangles with the same size.

Note that, in the embodiment of the present application, the filter unit 11 may include a first color filter 111 and a second color filter 112; the pixel unit 12 may include a first pixel unit 121 and a second pixel unit 122.

It is understood that, in the embodiment of the present application, the first color filter 111 and the second color filter 112 in the filter unit 11 are both equilateral triangles. Accordingly, the first pixel unit 121 and the second pixel unit 122 in the pixel unit 12 are also both equilateral triangles.

Further, in the embodiment of the present application, since the first color filter 111 and the second color filter 112 are both equilateral triangles, the filter unit 11 may constitute a hexagonal array color filter.

It should be noted that, in the embodiment of the present application, since the first pixel unit 121 and the second pixel unit 122 are equilateral triangles, the pixel unit 12 can constitute a hexagonal array pixel, and compared with a square array pixel, the hexagonal array pixel improves the pixel density of the CIS, and further improves the resolution of the CIS.

Further, in the embodiment of the present application, the readout circuit 13 may be connected to the pixel unit 12.

It should be noted that, in the embodiment of the present application, the first color filter 111 may be covered on the first pixel unit 121, and correspondingly, the second color filter 112 may be covered on the second pixel unit 122.

Further, in the embodiment of the present application, the first pixel unit 121 may include a first subpixel 121a and a second subpixel 121 b. Specifically, the first subpixel 121a is stacked on the second subpixel 121 b.

In the embodiment of the present application, the first PD column 101, the second PD column 102 and the third PD column 103 are respectively disposed in the first sub-pixel 121a, the second sub-pixel 121b and the second pixel unit 122. The first PD column 101, the second PD column 102, and the third PD column 103 are PD columns with three different size parameters.

For example, in the present application, the first PD column 101 may be disposed in the first sub-pixel 121a, the second PD column 102 may be disposed in the second sub-pixel 121b, and the third PD column 103 may be disposed in the second pixel unit 122. That is, in the present application, the PD columns provided in the first sub-pixel 121a, the second sub-pixel 121b, and the second pixel unit 122 are three types of columns different from each other.

It is understood that, in the embodiment of the present application, since the first pixel unit 121 includes the first sub-pixel 121a and the second sub-pixel 121b provided with two different PD columns, and the second pixel unit 122 is provided with another PD column, the complementary metal oxide image sensor 10 composed of the first pixel unit 121 and the second pixel unit 122 can realize absorption of different color light in incident light based on three different size parameters of the PD columns.

It should be noted that, in the embodiment of the present application, the first pixel unit 121 may be vertically divided into an upper layer region and a lower layer region from top to bottom.

Further, in the embodiment of the present application, the first sub-pixel 121a may be disposed in an upper layer region, and the second sub-pixel 121b may be disposed in a lower layer region. The first sub-pixel 121a is stacked on the second sub-pixel 121b along the light transmission direction.

Fig. 5 is a schematic diagram illustrating a second constitutional structure of the CIS, and as shown in fig. 5, the first pixel unit 121 is vertically divided into an upper region U and a lower region D from top to bottom along a light transmission direction. The first sub-pixel 121a is disposed in the upper region U, and the second sub-pixel 121b is disposed in the lower region D. The second sub-pixel 121b may be vertically disposed below the first sub-pixel 121 a.

It is understood that, in the embodiments of the present application, the complementary metal oxide image sensor 10 may dispose the first PD column 101, the second PD column 102, and the third PD column 103 in the first sub-pixel 121a, the second sub-pixel 121b, and the second pixel unit 122 in a variety of different ways.

It should be noted that, in the embodiment of the present application, at least one PD pillar may be disposed in each sub-pixel. For example, in the present application, 10 second PD pillars 102 may be disposed in the

first sub-pixel

121a, 10 third PD pillars 103 may be disposed in the

second sub-pixel

121b, and 10 first PD pillars 101 may be disposed in the second pixel unit 122.

Further, in the embodiment of the present application, the number of the first PD column 101, the second PD column 102 and the third PD column 103 may be the same or different, and the present application is not particularly limited.

It should be noted that, in the embodiment of the present application, the number of the first PD column 101, the second PD column 102 and the third PD column 103 may be determined by the size of the pixel unit 12, that is, the larger the first pixel unit 121 and the second pixel unit 122 are, the larger the number of the PD columns arranged in the first sub-pixel 121a, the second sub-pixel 121b and the second pixel unit 122 are. The smaller the first and

second pixel units

121 and 122 are, the smaller the number of PD pillars provided in the first, second and second sub-pixels 121a, 121b and 122 are.

Further, in the embodiment of the present application, the specific interval between every two PD pillars in the sub-pixel needs to be greater than 50 nm, that is, the interval distance between any two PD pillars disposed in the first sub-pixel 121a, the second sub-pixel 121b, and the second pixel unit 122 is greater than 50 nm. That is, in the present embodiment, the separation distance between any two PD pillars among the first PD pillar 101, the second PD pillar 102, and the third PD pillar 103 is greater than 50 nm.

It should be noted that, in the embodiment of the present application, the cmos image sensor 10 may absorb incident light through the first sub-pixel 121a, the second sub-pixel 121b, and the second pixel unit 122 in the first pixel unit 121, respectively, so as to obtain pixel values of different colors of light in the incident light. For example, the complementary metal oxide image sensor 10 absorbs green light, red light, and blue light of incident light by the first pixel unit 121 and the second pixel unit 122, respectively, the first PD column 101 in the first sub-pixel 121a may correspond to a G channel and output a green pixel value, the second PD column 102 in the second sub-pixel 121B may correspond to an R channel and output a red pixel value, and the third PD column 103 in the second pixel unit 122 may correspond to a B channel and output a blue pixel value.

Further, in the embodiment of the present application, the first pixel unit 121 and the second pixel unit 122 may be adjacently disposed, that is, the periphery of the first pixel unit 121 may be the second pixel unit 122, and correspondingly, the periphery of the second pixel unit 122 may be the first pixel unit 121. Fig. 6 is a top view of the positional relationship of the pixel units, and as shown in fig. 6, the first pixel unit 121 and the second pixel unit 122 may be adjacent to each other, that is, in the top view, all three pixel units adjacent to the first pixel unit 121 are the second pixel unit 122.

Based on the above fig. 6, fig. 7 is a schematic diagram of a cross section of a pixel unit, fig. 8 is a schematic diagram of a cross section of a pixel unit, and as shown in fig. 7 and 8, 10 first PD pillars 101 are disposed in the first sub-pixel 121a, 9 second PD pillars 102 and a circuit for connecting transfer gates are disposed in the

second sub-pixel

121b, and 10 third PD pillars 103 are disposed in the second pixel unit 122.

Further, in the embodiment of the present application, the complementary metal oxide image sensor 10 may absorb the first color light by the first PD column 101, may absorb the second color light by the second PD column 102, and may absorb the third color light by the third PD column 103. Among them, the first PD column 101, the second PD column 102, and the third PD column 103 may be sub-wavelength photodiodes. In particular, subwavelength refers to periodic (or aperiodic) structures with characteristic dimensions comparable to or smaller than the operating wavelength. The characteristic size of the sub-wavelength structure is smaller than the wavelength, and the reflectivity, the transmissivity, the polarization characteristic, the spectral characteristic and the like of the sub-wavelength structure all show the characteristics which are different from those of the conventional diffraction optical element, so that the sub-wavelength structure has greater application potential.

Specifically, in the embodiments of the present application, the first, second, and third color lights may include green, red, and blue lights among incident lights. For example, the first color light may be red light, the second color light may be green light, and the third color light may be blue light. That is, the cmos image sensor 10 can absorb green light, red light, and blue light of incident light by disposing the first PD column 101, the second PD column 102, and the third PD column in the first subpixel 121a, the second subpixel 121b, and the second pixel unit 122, respectively.

In the embodiment of the present application, since the first PD column 101, the second PD column 102 and the third PD column 103 can be respectively used for absorbing the first color light, the second color light and the third color light in the incident light, the first size parameter of the first PD column 101 can be determined by the first wavelength range corresponding to the first color light; a second dimension parameter of the second PD column 102 may be determined by a second wavelength range corresponding to the second color light; the third dimension parameter of the third PD column 103 may be determined by a third wavelength range corresponding to the third color light. For example, in the present application, if the first color light is green light, the second color light is blue light, and the third color light is red light, the first wavelength range corresponding to the first color light may be 492 nanometers to 577 nanometers; the second wavelength range corresponding to the second color light may be 440 nm to 475 nm; the third wavelength range corresponding to the third color light may be 625 nm to 740 nm.

Further, in the embodiment of the present application, it is precisely because the first sub-pixel 121a, the second sub-pixel 121b, and the second pixel unit 122 may include the first PD column 101, the second PD column 102, and the third PD column 103 with three different size parameters, respectively, and the first PD column 101, the second PD column 102, and the third PD column 103 may absorb the first color light, the second color light, and the third color light of the incident light, respectively, so that the first pixel unit 121 and the second pixel unit 122 may simultaneously absorb the light of the three RGB colors of the incident light through optical resonance, respectively. Specifically, just as the first PD column 101 and the second PD column 102 are stacked in the first pixel unit 121 in the pixel unit 12, the pixel unit 12 can achieve simultaneous absorption of different color lights by a single pixel through the first pixel unit 121.

It should be noted that, in the embodiments of the present application, the first dimension parameter includes a first diameter and a first thickness; the second dimensional parameters include a second diameter and a second thickness; the third dimensional parameter includes a third diameter and a third thickness. That is, in the present application, the first, second, and third dimensional parameters may characterize the diameter and thickness of the first, second, and

third PD pillars

101, 102, and 103, respectively.

Further, in the embodiment of the present application, the corresponding diameter of the PD pillars may be determined by the wavelength range of light that it absorbs correspondingly so that, for the first diameter, the second diameter, and the third diameter, if the first PD pillar 101 is used to absorb green light, that is, the first color light is green light, the first diameter thereof may be determined to be 90 nm by the first wavelength range; if the second PD column 102 is configured to absorb blue light, i.e., the second colored light is blue light, its second diameter may be determined to be 60nm by the second wavelength range; if the third PD column 103 is for absorbing red light, i.e. the third colored light is red light, its third diameter can be determined to be 120nm by a third wavelength range.

It should be noted that, in the embodiment of the present application, since the first sub-pixel 121a and the second sub-pixel 121b in the first pixel unit 121 are stacked and the second pixel unit 122 is independently disposed, the thickness of the PD column in the first sub-pixel 121a and the second sub-pixel 121b may be smaller than that in the second pixel unit 122. For example, if the first PD column 101 is disposed in the first sub-pixel 121a, the second PD column 102 is disposed in the second sub-pixel 121b, and the third PD column 103 is disposed in the second pixel unit 122, the first thickness of the first PD column 101 and the second thickness of the second PD column 102 are both smaller than the third thickness of the third PD column 103.

It is understood that, in the embodiments of the present application, in order to enhance the absorption of a certain color light, the thickness of the PD column may be increased correspondingly. Illustratively, if it is desired to increase the absorption of the first color light, the first thickness of the first PD column 101 may be increased appropriately.

It should be noted that, in the embodiment of the present application, although the larger the thickness of the PD column is, the higher the light absorption rate is, for the first pixel unit 121 including two kinds of PD columns, since one kind of PD column is used for absorbing one kind of color light, if the thickness is too large, part of other color light is absorbed, so that the absorption of the other kind of PD column to the other kind of color light is affected, when the thickness is increased, a value of the thickness needs to be balanced, and a maximum value of the thickness of each kind of PD column is limited, so as to ensure that the PD column is not interfered by the other color light when absorbing the corresponding color light.

Illustratively, in the present application, fig. 9 is a schematic diagram of absorption of incident light, as shown in fig. 9, when the first PD column 101 is used to absorb blue light, the second PD column 102 is used to absorb red light, and the third PD column 103 is used to absorb green light, after the incident light passes through the violet color filter P, firstly, after the blue light passes through the first PD column 101 array (the diameter of the first PD column 101 is about 60nm, the thickness is 80nm-1um, the absorption rate is higher the longer, the absorption rate can be as high as 98% at 1um, but the longer the absorption rate can absorb red light, which needs to be balanced), due to the resonant absorption of the first PD column 101 array, 95% of the blue light can be absorbed and converted into an electrical signal which is stored in the first PD, and the signal of the B channel is read out, at this time, the red light is hardly absorbed. When the incident light reaches the second PD column 102 below, since blue light is almost absorbed and only red light remains, the red light is absorbed and converted into an electrical signal by the second PD column 102 (with a thickness of 1um or more, the thicker the red light is absorbed), and the R signal is read out. Accordingly, for a general G pixel, incident light passes through a green color filter and is absorbed by the third PD column 103 and converted into an electrical signal, which is read out to obtain a G signal.

Further, in the embodiment of the present application, when the first color light is blue light, the second color light is green light, and the third color light is red light, the first color filter 111 is used to select blue light and green light in the incident light, that is, the first color filter 111 may be a cyan color filter, and the second color filter 112 is used to select red light in the incident light, that is, the second color filter 112 may be a red color filter. When the first color light is red light, the second color light is green light, and the third color light is blue light, the first color filter 111 is used to select red light and green light in the incident light, that is, the first color filter 111 may be a yellow color filter, and the second color filter 112 is used to select blue light in the incident light, that is, the second color filter 112 may be a blue color filter. When the first color light is red light, the second color light is blue light, and the third color light is green light, the first color filter 111 is used for selecting blue light and red light in the incident light, that is, the first color filter 111 may be a violet color filter, and the second color filter 112 is used for selecting green light in the incident light, that is, the second color filter 112 may be a green color filter.

For example, in the embodiment of the present application, if the first color light is blue light, the second color light is red light, and the third color light is green light, the first sub-pixel 121a may absorb the blue light through the first PD column 101, the second sub-pixel 121b may absorb the red light through the second PD column 102, and the second pixel unit 122 may absorb the green light through the third PD column 103. Then, fig. 10 is a first schematic diagram of a filter unit, and as shown in fig. 10, the filter unit in the present application may be composed of a first color filter 111 and a second color filter 112, wherein the first color filter 111 is a violet color filter P that can transmit blue light and red light, and the second color filter 112 is a green color filter G that can transmit green light. Specifically, the first and second sub-pixels 121a and 121b for absorbing blue and red light may be under the first color filter 111, and the second pixel unit 122 for absorbing green light may be under the second color filter 112.

For example, in the embodiment of the present application, if the first color light is blue light, the second color light is green light, and the third color light is red light, then the first sub-pixel 121a may absorb the blue light through the first PD column 101, the second sub-pixel 121b may absorb the green light through the second PD column 102, and the second pixel unit 122 may absorb the red light through the third PD column 103, then fig. 11 is a second schematic diagram of a filter unit, as shown in fig. 11, the filter unit in the present application may be composed of a first color filter 111 and a second color filter 112, where the first color filter 111 is a cyan color filter C that can transmit the blue light and the green light, and the second color filter 112 is a color filter R that can transmit the red light. Specifically, the first and second sub-pixels 121a and 121b for absorbing blue and green light may be under the first color filter 111, and the second pixel unit 122 for absorbing red light may be under the second color filter 112.

For example, in the embodiment of the present application, if the first color light is green light, the second color light is red light, and the third color light is blue light, then the first sub-pixel 121a may absorb the green light through the first PD column 101, the second sub-pixel 121B may absorb the red light through the second PD column 102, and the second pixel unit 122 may absorb the blue light through the third PD column 103, then fig. 12 is a third schematic diagram of a filtering unit, as shown in fig. 12, the filtering unit in the present application may be composed of a first color filter 111 and a second color filter 112, where the first color filter 111 is a yellow color filter Y that may transmit the green light and the red light, and the second color filter 112 is a color filter B that may transmit the blue light. Specifically, the first color filter 111 may be thereunder a first subpixel 121a and a second subpixel 121b for absorbing green and red light, and the second color filter 112 may be thereunder a second pixel unit 122 for absorbing blue light.

Further, in an embodiment of the present application, fig. 13 is a schematic diagram of a composition structure of a CIS, and as shown in fig. 13, the complementary metal oxide image sensor 10 may further include: a lens 14, wherein the lens 14 may be disposed above the filter unit 11 in the light transmission direction, and specifically, the lens 14 may be disposed above the first color filter 111 and the second color filter 112 in the light transmission direction, respectively.

It should be noted that, in the embodiment of the present application, the lens 14 may be used to condense incident light.

Further, in the embodiment of the present application, in the pixel unit 12, the first sub-pixel 121a in the first pixel unit 121 may be disposed above the second sub-pixel 121b in a stacked manner in the light transmission direction, that is, the first PD column 101 is disposed above the second PD column 102 in a vertically stacked manner. Specifically, in the present application, the first pixel unit 121 may absorb a first color light of the incident light by the first PD column 101 of the upper layer and then may absorb a second color light of the incident light by the second PD column 102 of the lower layer through the arrangement of the vertically stacked PD columns.

Accordingly, in the embodiment of the present application, in the pixel unit 12, the second pixel unit 122 absorbs the third color light of the incident light through the third PD column 103 provided.

As can be seen from this, in the present application, the cmos image sensor 10 can achieve simultaneous absorption of different color lights in incident light through the first pixel unit 121 and the second pixel unit 122.

Further, in the embodiment of the present application, the readout circuit 13 in the cmos image sensor 10 may include a first readout circuit 131, a second readout circuit 132, and a third readout circuit 133. Specifically, the photodiode of each layer is connected with a corresponding one of the readout circuits.

It is understood that, in the embodiment of the present application, the first readout circuit 131 may be connected to the first subpixel 121a for reading out the first electrical signal; the second readout circuit 132 may be connected to the second subpixel 121b for reading out a second electrical signal; a third readout circuit 133 may be connected to the second pixel unit 122 for reading out a third electrical signal.

For example, in an embodiment of the present application, the first color filter 111 is configured to selectively absorb the first color light and the second color light, the second color filter 112 is configured to selectively absorb the third color light, fig. 14 is a schematic diagram of a composition structure of the CIS, as shown in fig. 14, after incident light passes through the first color filter 111, the first color light and the second color light in the incident light are transmitted, light of other colors is filtered, when the first color light and the second color light pass through the first pixel unit 121, based on resonance absorption of the first PD column 101 in the first sub-pixel 121a, 95% or more of the first color light is absorbed and converted into an electrical signal for storage, and the second color light is hardly absorbed, so that a first electrical signal corresponding to the first color light can be read; then, the second color light reaches the second PD column 102 stacked under the first PD column 101, and since almost all of the first color light is absorbed and only the second color light remains, the second color light is absorbed by the second PD column 102 in the second sub-pixel 121b and converted into an electric signal to be read out, so that a second electric signal corresponding to the second color light can be obtained. Correspondingly, after the incident light passes through the second color filter 112, the third color light in the incident light is transmitted, the lights of other colors are filtered, and when the third color light passes through the second pixel unit 122, based on the resonant absorption of the third PD column 103 in the second pixel unit 122, the third color light is absorbed by the second pixel unit 122 and is converted into an electrical signal for reading, so that a third electrical signal corresponding to the third color light can be obtained. Specifically, the first PD column 101 in the first pixel unit 121 is connected to the first readout circuit 131 to read out the first electric signal, and the second PD column 102 is connected to the second readout circuit 132 to read out the second electric signal; the third PD column 103 in the second pixel unit 122 is connected to the third readout circuit 133 to read out the third electrical signal. Eventually, simultaneous readout of all signals corresponding to incident light is achieved by the pixel unit 12 and the readout circuit 13.

Further, in the embodiment of the present application, the corresponding shapes of the first PD column 101, the second PD column 102, and the third PD column 103 may include a cylinder or a prism, and the specific shape may be selected according to actual situations, which is not specifically limited in the embodiment of the present application.

It should be noted that the cmos image sensor 10 proposed in the present application may be FSI or BSI, and the embodiment of the present application takes BSI as an example for description, but is not limited specifically.

The embodiment of the application provides a CMOS image sensor CIS, which comprises a light filtering unit, a pixel unit and a reading circuit, wherein the light filtering unit and the pixel unit are both equilateral triangles, the light filtering unit comprises a first color filter and a second color filter, and the pixel unit comprises a first pixel unit and a second pixel unit; the readout circuit is connected with the pixel unit; the first color filter is covered on the first pixel unit, and the second color filter is covered on the second pixel unit; the first pixel unit comprises a first sub-pixel and a second sub-pixel, wherein the first sub-pixel is stacked on the second sub-pixel; a first PD column is arranged in the first sub-pixel, a second PD column is arranged in the second sub-pixel, and a third PD column is arranged in the second pixel unit. That is, in the embodiment of the present application, a pixel unit in the CIS may include two sub-pixels vertically stacked, each sub-pixel has a PD pillar disposed therein for absorbing one color light, and in combination with a filter covering the pixel unit, a single pixel unit selectively absorbs different color lights of incident light at the same time. Therefore, in the application, the CIS can simultaneously acquire light signals of multiple colors through the first pixel unit absorbing the first color light and the second pixel unit absorbing the second color light and the second pixel unit absorbing the third color light, so that the utilization rate of the light signals can be improved, the signal-to-noise ratio of the CIS is improved, and the efficiency and the quality of image processing are improved.

Based on the foregoing embodiments, a further embodiment of the present application provides an image processing apparatus including a cmos image sensor, fig. 15 is a schematic diagram of a composition structure of the image processing apparatus according to the embodiments of the present application, as shown in fig. 15, in an embodiment of the present invention, an image processing apparatus 20 may include a processor 21, a memory 22 storing executable instructions of the processor 21, and the cmos image sensor 10, and further, the image processing apparatus 20 may further include a communication interface 23, and a bus 24 for connecting the processor 21, the memory 22, and the communication interface 23.

It should be noted that, in the embodiment of the present application, the complementary metal oxide image sensor 10 in the image processing apparatus 20 may include a filter unit, a pixel unit, and a readout circuit. Further, the image sensor 10 may further include a lens.

It should be noted that, in the embodiments of the present application, the filter unit and the pixel unit are all equilateral triangles with the same size. Wherein the filtering unit may include a first color filter and a second color filter; the pixel unit may include a first pixel unit and a second pixel unit.

Further, in embodiments of the present application, a readout circuit may be connected to the pixel cell.

It should be noted that, in the embodiments of the present application, the first color filter may be covered on the first pixel unit, and correspondingly, the second color filter may be covered on the second pixel unit.

Further, in an embodiment of the present application, the first pixel unit may include a first sub-pixel and a second sub-pixel. Specifically, the first subpixel is stacked over the second subpixel.

It is to be understood that, in the embodiments of the present application, the first color filter and the second color filter in the filter unit are both equilateral triangles. Correspondingly, the first pixel unit and the second pixel unit in the pixel unit are also both equilateral triangles.

Further, in the embodiment of the present application, since the first color filter and the second color filter are both equilateral triangles, the filter unit may constitute a hexagonal array of color filters.

It should be noted that, in the embodiment of the present application, since the first pixel unit and the second pixel unit are equilateral triangles, the pixel units may form a hexagonal array pixel, and compared with a square array pixel, the hexagonal array pixel improves the pixel density of the CIS, and further improves the resolution of the CIS.

In the embodiments of the present application, a first PD column, a second PD column, and a third PD column are respectively disposed in the first sub-pixel, the second sub-pixel, and the second pixel unit. Wherein, the first PD column, the second PD column and the third PD column are PD columns with three different size parameters.

For example, in the present application, a first PD column may be disposed in the first sub-pixel, a second PD column may be disposed in the second sub-pixel, and a third PD column may be disposed in the second pixel unit. That is, in the present application, the PD columns provided in the first sub-pixel, the second sub-pixel, and the second pixel unit are three types of columns different from each other.

It is understood that, in the embodiment of the present application, since the first pixel unit includes the first sub-pixel and the second sub-pixel provided with two different PD pillars and the second pixel unit has another PD pillar provided therein, the cmos image sensor 10 configured by the first pixel unit and the second pixel unit can achieve absorption of different colors of light in incident light based on three different size parameters of the PD pillars.

It should be noted that, in the embodiment of the present application, the first pixel unit may be vertically divided into an upper layer region and a lower layer region from top to bottom.

Further, in an embodiment of the present application, the first sub-pixel may be disposed in an upper layer region, and the second sub-pixel may be disposed in a lower layer region. The first sub-pixel is stacked on the second sub-pixel along the light transmission direction.

It is understood that, in the embodiments of the present application, the complementary metal oxide image sensor 10 may dispose the first PD column, the second PD column, and the third PD column in the first sub-pixel, the second sub-pixel, and the second pixel unit in a variety of different ways.

It should be noted that, in the embodiment of the present application, at least one PD pillar may be disposed in each sub-pixel. The number of the first PD column, the second PD column, and the third PD column may be the same or different, and the application is not particularly limited.

It is understood that, in the embodiment of the present application, the number of the first PD column, the second PD column, and the third PD column may be determined by the size of the pixel unit, that is, the larger the first pixel unit and the second pixel unit, the larger the number of the PD columns disposed in the first sub-pixel, the second sub-pixel, and the second pixel unit 122. The smaller the first pixel unit and the second pixel unit are, the smaller the number of PD columns provided in the first sub-pixel, the second sub-pixel, and the second pixel unit is.

It should be noted that, in the embodiment of the present application, the complementary metal oxide image sensor 10 may absorb the incident light through the first sub-pixel, the second sub-pixel, and the second pixel unit in the first pixel unit and the second pixel unit, respectively, so as to obtain the pixel values of the light with different colors in the incident light. Specifically, the complementary metal oxide image sensor 10 may absorb the first color light by using the first PD column, may absorb the second color light by using the second PD column, and may absorb the third color light by using the third PD column. Wherein the first, second and third PD pillars may be sub-wavelength photodiodes.

Further, in an embodiment of the present application, the first color light, the second color light, and the third color light may include green light, red light, and blue light of incident light.

It should be noted that, in the embodiment of the present application, since the first color filter disposed in the cmos image sensor 10 covers the first pixel unit, the first color filter can select the first color light and the second color light of the incident light and filter the third color light, and further, the cmos image sensor 10 can select and absorb the first color light and the second color light of the incident light through the first sub-pixel and the second sub-pixel in the first pixel unit and the first color filter covering the first pixel unit.

It should be noted that, in the embodiment of the present application, since the second color filter disposed in the cmos image sensor 10 covers the second pixel unit, the second color filter can select the third color light of the incident light and filter out the first color light and the second color light. Further, the cmos image sensor 10 can select and absorb the third color light of the incident light through the second pixel unit and the second color filter covering the second pixel unit.

Further, in the embodiment of the present application, the color filter may be a violet color filter if the color filter is used to select blue and red light, a yellow color filter if the color filter is used to select green and red light, and a cyan color filter if the color filter is used to select blue and green light.

It should be noted that, in the embodiments of the present application, the lens may be used for converging incident light, and the lens may be disposed above the filtering unit along the light transmission direction, and specifically, the lens may be disposed above the first color filter and the second color filter along the light transmission direction, respectively.

Further, in embodiments of the present application, the readout circuitry may include a first readout circuitry, a second readout circuitry, and a third readout circuitry. Wherein the first readout circuit may be connected to the first subpixel for reading out the first electrical signal; the second readout circuit may be connected to the second subpixel for reading out the second electrical signal; the third readout circuit may be connected to the second pixel unit for reading out the third electrical signal.

It is understood that, in the embodiment of the present Application, the processor 21 may be at least one of an Application Specific Integrated Circuit (ASIC), a Digital Signal Processor (DSP), a Digital Signal Processing Device (DSPD), a ProgRAMmable Logic Device (PLD), a Field ProgRAMmable Gate Array (FPGA), a Central Processing Unit (CPU), a controller, a microcontroller, and a microprocessor. It is understood that the electronic devices for implementing the processor functions may be other devices, and the embodiments of the present application are not limited in particular. The display 1 may further comprise a memory 22, which memory 22 may be connected to the processor 21, wherein the memory 22 is adapted to store executable program code comprising computer operating instructions, and wherein the memory 22 may comprise a high speed RAM memory and may further comprise a non-volatile memory, such as at least two disk memories.

In the embodiment of the present application, the bus 24 is used to connect the communication interface 23, the processor 21, and the memory 22 and the intercommunication among these devices.

In an embodiment of the present application, the memory 22 is used for storing instructions and data.

In practical applications, the Memory 22 may be a volatile Memory (volatile Memory), such as a Random-Access Memory (RAM); or a non-volatile Memory (non-volatile Memory), such as a Read-Only first Memory (ROM), a flash Memory (flash Memory), a Hard disk (Hard disk Drive, HDD) or a Solid-State Drive (SSD); or a combination of the above types of memories and provides instructions and data to the processor 21.

In addition, each functional module in this embodiment may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware or a form of a software functional module.

Based on the understanding that the technical solution of the present embodiment essentially or a part contributing to the prior art, or all or part of the technical solution, may be embodied in the form of a software product stored in a storage medium, and include several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor (processor) to execute all or part of the steps of the method of the present embodiment. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The application provides an image processing device, a CIS is arranged in the image processing device, the CIS comprises a light filtering unit, a pixel unit and a reading circuit, wherein the light filtering unit and the pixel unit are all equilateral triangles, the light filtering unit comprises a first color filter and a second color filter, and the pixel unit comprises a first pixel unit and a second pixel unit; the readout circuit is connected with the pixel unit; the first color filter is covered on the first pixel unit, and the second color filter is covered on the second pixel unit; the first pixel unit comprises a first sub-pixel and a second sub-pixel, wherein the first sub-pixel is stacked on the second sub-pixel; a first PD column is arranged in the first sub-pixel, a second PD column is arranged in the second sub-pixel, and a third PD column is arranged in the second pixel unit. That is, in the embodiment of the present application, a pixel unit in the CIS may include two sub-pixels vertically stacked, each sub-pixel has a PD pillar disposed therein for absorbing one color light, and in combination with a filter covering the pixel unit, a single pixel unit selectively absorbs different color lights of incident light at the same time. Therefore, in the application, the CIS can simultaneously acquire light signals of multiple colors through the first pixel unit absorbing the first color light and the second pixel unit absorbing the second color light and the second pixel unit absorbing the third color light, so that the utilization rate of the light signals can be improved, the signal-to-noise ratio of the CIS is improved, and the efficiency and the quality of image processing are improved.

It will be apparent to those skilled in the art that embodiments of the present application may be provided as a method, display, or computer program product. Accordingly, the present application may take the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of implementations of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart block or blocks and/or flowchart block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks in the flowchart and/or block diagram block or blocks.

The above description is only a preferred embodiment of the present application, and is not intended to limit the scope of the present application.

Claims

1. A CMOS Image Sensor (CIS), comprising: the pixel array comprises a light filtering unit, a pixel unit and a reading circuit, wherein the light filtering unit and the pixel unit are both in an equilateral triangle shape, the light filtering unit comprises a first color filter and a second color filter, and the pixel unit comprises a first pixel unit and a second pixel unit;

the readout circuit is connected with the pixel unit;

a first Photodiode (PD) pillar is arranged in the first sub-pixel, a second PD pillar is arranged in the second sub-pixel, and a third PD pillar is arranged in the second pixel unit.

2. The CIS of claim 1,

the first pixel unit is vertically divided into an upper layer area and a lower layer area from top to bottom;

the first sub-pixel is arranged in the upper layer area, the second sub-pixel is arranged in the lower layer area, and the first sub-pixel is stacked on the second sub-pixel along the light transmission direction.

3. The CIS of claim 1,

a first dimension parameter of the first PD column is determined by a first wavelength range corresponding to a first color light;

a second size parameter of the second PD column is determined by a second wavelength range corresponding to the second chromatic light;

and a third dimension parameter of the third PD column is determined by a third wavelength range corresponding to the third colored light.

4. The CIS of claim 3,

the first color filter is used for selecting the first color light and the second color light in incident light;

the second color filter is used for selecting the third color light in the incident light.

5. The CIS of claim 4 wherein when the first color light is blue light, the second color light is green light, and the third color light is red light,

the first color filter is a cyan color filter and the second color filter is a red color filter.

6. The CIS of claim 4 wherein when the first color light is red, the second color light is green, and the third color light is blue,

the first color filter is a yellow color filter and the second color filter is a blue color filter.

7. The CIS of claim 4 wherein when the first color light is red, the second color light is blue, and the third color light is green,

the first color filter is a violet color filter and the second color filter is a green color filter.

8. The CIS of claim 3,

the first sub-pixel absorbs the first color light through the first PD column, and the second sub-pixel absorbs the second color light through the second PD column;

the second pixel unit absorbs the third color light through the third PD column.

9. The CIS of claim 1, further comprising: a lens, wherein the lens is disposed above the filter unit in a light transmission direction.

10. The CIS of claim 1,

the corresponding shapes of the first PD column, the second PD column, and the third PD column include a cylinder or a prism.

11. The CIS of claim 1 wherein the readout circuit comprises a first readout circuit, a second readout circuit, and a third readout circuit,

the first readout circuit is connected with the first sub-pixel and used for reading out a first electric signal;

the second reading circuit is connected with the second sub-pixel and used for reading a second electric signal;

the third readout circuit is connected to the second pixel unit and configured to read out a third electrical signal.

12. The CIS according to any of claims 1 to 11,

the first, second, and third PD columns are all sub-wavelength PD columns.

13. An image processing apparatus, comprising a CIS including a filter unit, a pixel unit, and a readout circuit, wherein the filter unit and the pixel unit are each an equilateral triangle, the filter unit includes a first color filter and a second color filter, and the pixel unit includes a first pixel unit and a second pixel unit; the readout circuit is connected with the pixel unit; the first color filter is covered on the first pixel unit, and the second color filter is covered on the second pixel unit; the first pixel unit comprises a first sub-pixel and a second sub-pixel, wherein the first sub-pixel is stacked on the second sub-pixel; a first PD pillar is arranged in the first sub-pixel, a second PD pillar is arranged in the second sub-pixel, and a third PD pillar is arranged in the second pixel unit.