CN105812685A - Pixel array and method for improving light response uniformity of pixel array - Google Patents

Abstract

A pixel array and a method for improving the photoresponse uniformity of the pixel array. Wherein, the pixel array includes a plurality of pixels distributed in an array, and the pixel array also includes: a first area whose distance to the straight line where the optical axis of the lens is located is less than or equal to the first distance; a distance to the straight line where the optical axis of the lens is located is greater than the first The second area of the distance; each pixel located in the first area has a first photosensitive area; each pixel located in the second area has a second photosensitive area; the second photosensitive area is larger than the first photosensitive area A photosensitive area. The pixel array can avoid the problem of photoresponse difference caused by the inherent cosine fourth power exposure rule, and improve the uniformity of pixel photoresponse in different regions of the pixel array.

Description

Pixel array and method for improving photoresponse uniformity of pixel array

technical field

The invention relates to the field of semiconductor manufacturing, in particular to a pixel array and a method for improving the photoresponse uniformity of the pixel array.

Background technique

An image sensor is a device that converts optical information into electrical signals. Image sensors can be further divided into two different types: Complementary Metal Oxide Semiconductor (CMOS) image sensors and Charge Coupled Device (CCD) image sensors. Among them, the CMOS image sensor has the advantages of simple structure, small size and convenient application, and has a wide range of uses.

For an image sensor, the light intensity reaching the sensor through the lens is different on the optical axis of the image plane and its surroundings. The brightness around the image plane is called the peripheral light amount, which is expressed as a percentage of the relative brightness to the center, and is the Relative Illumination (RelativeIllumination) )curve. The amount of peripheral light is affected by the fourth power law of cosine of the lens and the vignetting phenomenon, so the brightness will inevitably decrease compared with the central part. Causes phenomena such as vignetting around the sensor. That is, the incident light parallel to the optical axis of the lens gathers in the center of the screen to form an image. Assuming its illuminance is I ₀ , then the oblique light that is not parallel to the optical axis is incident at an arbitrary angle θ with the optical axis, and the image surface illuminance at this time is I _θ , then there is the following relationship:

I _θ = I ₀ cos ⁴ θ

The corresponding relative illuminance curve is shown in Figure 1. The brightness of an oblique ray image is proportional to the fourth power of the cosine of this oblique angle. Therefore, compared with the center part of the frame, the image will be darker towards the edge. Especially with a wide-angle lens or a large aperture lens, it is more affected by edge light reduction.

Due to the above cosine fourth power exposure law, there is a problem of light response difference between pixels in different regions in the existing pixel array.

In order to reduce the vignetting of the sensor caused by cosine fourth power and vignetting, the vignetting phenomenon can be eliminated by reducing the aperture.

As shown in FIG. 2 , the existing method usually designs a complex lens combination 200 to increase the aperture efficiency, so as to prevent the light amount reaching the periphery of the pixel array 100 from being less, so as to reduce the light response difference caused by the cosine fourth power exposure rule. Purpose. The straight line where the dotted line in FIG. 2 is located is the straight line where the optical axis of the lens is located, and the position where the optical axis of the lens passes through the pixel array 100 is the midpoint 101 of the pixel array 100 .

Another existing method is to add a mask layer above the pixels, and control the amount of light entering the pixels through different opening sizes to change the response of each pixel. However, this method increases the complexity of the process.

However, neither of the above two methods can avoid the problem of photoresponse differences caused by the inherent cosine fourth power exposure rule.

Contents of the invention

The problem to be solved by the present invention is to provide a pixel array and a method for improving the uniformity of photoresponse of the pixel array, so as to solve the problem of difference in photoresponse of pixels in different regions.

In order to solve the above problems, the present invention provides a pixel array, the pixel array includes a plurality of pixels distributed in an array, and the pixel array includes:

The first area whose distance to the straight line where the optical axis of the lens is located is less than or equal to the first distance;

The second area whose distance to the straight line where the optical axis of the lens is located is greater than the first distance;

Each pixel located in the first area has a first photosensitive area;

Each pixel located in the second area has a second photosensitive area;

The second photosensitive area is larger than the first photosensitive area.

Optionally, the minimum side length of the pixel array is more than 2.84 mm, and the first distance ranges from 1.29 mm to 1.42 mm.

Optionally, the size range of the first photosensitive area is 0.589 μm ² to 0.711 μm ² , and the second photosensitive area is 1.8 times to 2.0 times that of the first photosensitive area.

Optionally, the distance from the second area to the straight line where the optical axis of the lens is located is less than or equal to the second distance, and the pixel array further includes:

The third area whose distance to the straight line where the optical axis of the lens is located is greater than the second distance;

Each pixel located in the third area has a third photosensitive area;

The third photosensitive area is larger than the second photosensitive area.

Optionally, the minimum side length of the pixel array is more than 2.84mm, the first distance is 0.91mm-1.00mm, and the second distance is 1.29mm-1.42mm.

Optionally, the size range of the first photosensitive area is 0.589 μm ² to 0.711 μm ² , the second photosensitive area is 1.6 to 1.7 times the first photosensitive area, and the third photosensitive area is the 1.8 to 2.0 times the second photosensitive area.

Optionally, the distance from the third area to the straight line where the optical axis of the lens is located is less than or equal to the third distance, and the pixel array further includes:

The fourth area whose distance to the straight line where the optical axis of the lens is located is greater than the third distance;

Each pixel located in the fourth area has a fourth photosensitive area;

The fourth photosensitive area is larger than the third photosensitive area.

Optionally, the distance between the fourth area and the straight line where the optical axis of the lens is located is less than or equal to the fourth distance, and the pixel array further includes:

The fifth area whose distance to the straight line where the optical axis of the lens is located is greater than the fourth distance;

Each pixel located in the fifth area has a fifth photosensitive area;

The fifth photosensitive area is larger than the fourth photosensitive area.

In order to solve the above problems, the present invention also provides a method for improving the photoresponse uniformity of the pixel array, including:

providing a pixel array comprising a plurality of pixels arranged in an array;

Setting the area in the pixel array whose distance to the straight line where the optical axis of the lens is located is less than or equal to the first distance as the first area;

Setting the area in the pixel array whose distance to the straight line where the optical axis of the lens is located is greater than the first distance as the second area;

setting each pixel in the first area to have a first photosensitive area;

setting each pixel in the second area to have a second photosensitive area;

The second photosensitive area is set to be larger than the first photosensitive area to reduce the photoresponse difference between the pixels in the first area and the pixels in the second area.

Optionally, the method also includes:

Setting the distance from the second area to the straight line where the optical axis of the lens is located is less than or equal to the second distance;

Setting the area in the pixel array whose distance to the straight line where the optical axis of the lens is located is greater than the second distance as the third area;

setting each pixel in the third area to have a third photosensitive area;

The third light-sensing area is set larger than the second light-sensing area to reduce the light response difference between the pixels in the second area and the pixels in the third area.

Compared with the prior art, the technical solution of the present invention has the following advantages:

In the technical solution of the present invention, the pixel array is divided into a first area and a second area, and the distance between the pixels in the first area and the straight line where the optical axis of the lens is located is less than or equal to the first distance. Other pixels in the pixel array are located in the second area. Each pixel located in the first area has a first photosensitive area, each pixel located in the second area has a second photosensitive area, and the second photosensitive area is larger than the first photosensitive area. By setting the second photosensitive area larger than the first photosensitive area, the photosensitive difference between the pixels in the first area and the pixels in the second area can be adjusted, thereby avoiding the problem of photoresponse differences caused by the inherent cosine fourth power exposure law, thereby improving The uniformity of the photoresponse of pixels in different regions of the pixel array.

Further, the second photosensitive area is controlled at 1.8 to 2.0 times of the first photosensitive area. Calculated according to the cosine quadratic curve, the ratio of the light intensity at the first distance to the center of the pixel array is about (1/1.8)~(1/2.0), and then according to the relationship of the light intensity ratio, the second photosensitive area is controlled to be about The first light-sensing area is 1.8-2.0 times, so as to ensure that the second pixel in the second area can achieve the photoresponse sensitivity roughly equivalent to that of the first pixel in the first area.

Description of drawings

Figure 1 is the relative illuminance curve under the influence of cosine fourth power exposure rule;

Fig. 2 is a structural schematic diagram of an existing pixel array and lens combination;

Fig. 3 is a schematic diagram of a pixel array provided by an embodiment of the present invention;

FIG. 4 is a schematic diagram of a pixel array provided by another embodiment of the present invention;

5 is a schematic cross-sectional view of the pixel array shown in FIG. 4;

6 is an exposure time-gray value curve corresponding to pixels in different regions of the existing pixel array;

FIG. 7 is an exposure time-gray value curve corresponding to pixels in different regions of the pixel array shown in FIG. 4 .

detailed description

In order to solve the above-mentioned problem of photoresponse difference, the present invention provides a new pixel array, which is usually designed so that pixels in different regions have different photosensitive areas, and the closer to the area where the optical axis of the lens is located, the smaller the photosensitive area of the pixel. The farther away from the straight line where the optical axis of the lens is located, the larger the photosensitive area of the pixel. The larger the photosensitive area of a pixel, the more photons it can receive under the same lighting conditions and exposure time, and the correspondingly more charges will be generated, which compensates for the surrounding area far away from the optical axis of the lens due to the cosine fourth power exposure law. The influence of the reduction of the amount of light in the area, so that the pixels in different pixel areas have roughly the same photosensitivity, avoid the problem of light response differences caused by the inherent cosine fourth power exposure rule, and improve the uniformity of pixel light response in different areas of the pixel array.

In order to make the above objects, features and advantages of the present invention more comprehensible, specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

An embodiment of the present invention provides a pixel array 300 , please refer to FIG. 3 .

The pixel array 300 includes a plurality of pixels (not all shown) distributed in an array, the pixel array 300 includes a first zone Z31 whose distance to the straight line where the optical axis of the lens is located is less than or equal to the first distance D31, and a distance to the optical axis of the lens The second zone Z32 where the distance of the straight line is greater than the first distance D31. The pixels in the first zone Z31 are first pixels P31, and one of the first pixels P31 is shown in FIG. 3 as an example. The pixels in the second area Z32 are the second pixels P32, and one of the second pixels P32 is shown in FIG. 3 as an example. All the first pixels P31 and the second pixels P32 are the plurality of pixels included in the above-mentioned pixel array 300 . Wherein, each pixel located in the first zone Z31 has a first photosensitive area, that is, the first pixel P31 has a first photosensitive area. Each pixel located in the second zone Z32 has a second photosensitive area, that is, the second pixel P32 has a second photosensitive area. Moreover, the second photosensitive area is larger than the first photosensitive area.

In this embodiment, the planar shape of the pixel array 300 may be a rectangle, and the pixel array 300 has a rectangular center 301 . The rectangle center 301 is also the position where the line where the optical axis of the lens is located passes through the pixel array 300 (refer to FIG. 2 ).

In this embodiment, the minimum side length of the rectangular pixel array 300 (the minimum side length is the length of the two short sides of the rectangle parallel to each other) can be more than 2.84mm, so as to ensure that the number of pixels in the entire pixel array 300 is high (for example 5M or more). For example, specifically, the minimum side length of the pixel array 300 may be 2.84 mm.

In this embodiment, considering that the minimum side length of the rectangular pixel array 300 can be more than 2.84 mm, the size range of the first distance D31 can be 1.29 mm to 1.42 mm, that is, the distance from all the first pixels P31 to the center of the rectangle 301 The distances are all less than 1.29mm, or both are less than 1.42mm, for example, can be specifically 1.42mm. Since the first distance D31 is exactly half the length of the short side of the pixel array 300 , the first zone Z31 is just an inscribed circle with the center of the rectangle 301 as the center. In other embodiments, the diameter of the first zone Z31 may be less than 1.42mm. Correspondingly, at this time, the first zone Z31 is a circular area with the center of the rectangle 301 as the center, and the circular area is located in the rectangular pixel array 300. .

In this embodiment, the size range of the first photosensitive area may be 0.589 μm ² to 0.711 μm ² . Pixels located in the first zone Z31 receive relatively strong illuminance. Therefore, when the radius of the first zone Z31 is 1.29mm˜1.42mm (that is, when the size of the first distance D31 is 1.29mm˜1.42mm), the The above-mentioned first photosensitive area can be relatively small, that is, it can be selected from 0.589 μm ² to 0.711 μm ² , so as to ensure that the first pixel P31 has sufficient photoresponse sensitivity, and to prevent the photoresponse difference between the first pixel P31 and the second pixel P32 increase.

In this embodiment, the second photosensitive area is controlled to be 1.8 to 2.0 times the first photosensitive area. Calculated according to the cosine quadratic curve shown in Figure 2, the light quantity ratio between the first distance D31 and the center 301 is about (1/1.8)～(1/2.0), and then according to the relationship between the light quantity ratio, control the second The light-sensing area is approximately 1.8-2.0 times the first light-sensing area, so as to ensure that the second pixel P32 in the second zone Z32 can achieve a photoresponse sensitivity roughly equivalent to that of the first pixel P31 in the first zone Z31.

In the pixel array 300 provided in this embodiment, the pixel array 300 is divided into a first zone Z31 and a second zone Z32, and the distance between the pixels in the first zone Z31 and the straight line where the optical axis of the lens is located is less than or equal to the first distance D31. Some of the pixels are the first pixels P31. Other pixels in the pixel array 300 are located in the second region Z32, and this part of pixels is the second pixel P32. Moreover, the first pixel P31 has a first light-sensing area, the second pixel P32 has a second light-sensing area, and the second light-sensing area is larger than the first light-sensing area. By setting the second photosensitive area larger than the first photosensitive area, the photosensitive difference between the second pixel P32 and the first pixel P31 can be adjusted, thereby avoiding the problem of photoresponse differences caused by the inherent cosine fourth power exposure law, and improving the pixel array in different areas. Uniformity of pixel light response.

Another embodiment of the present invention provides another pixel array 400 , please refer to FIG. 4 .

The pixel array 400 includes a plurality of pixels (not all shown) distributed in an array, the pixel array 400 includes a first zone Z41 whose distance to the straight line where the optical axis of the lens is located is less than or equal to the first distance D41, and a distance to the optical axis of the lens The second zone Z42 where the distance of the straight line is greater than the first distance D41, and the distance from the second zone Z42 of the pixel array 400 to the straight line where the optical axis of the lens is located is less than or equal to the second distance D42. The pixels in the first zone Z41 are first pixels P41, and one of the first pixels P41 is shown in FIG. 4 as an example. The pixels in the second area Z42 are the second pixels P42, and one of the second pixels P42 is shown in FIG. 4 as an example. Wherein, each pixel located in the first zone Z41 has a first photosensitive area, that is, the first pixel P41 has a first photosensitive area. Each pixel located in the second zone Z42 has a second photosensitive area, that is, the second pixel P42 has a second photosensitive area. Moreover, the second photosensitive area is larger than the first photosensitive area.

Please continue to refer to FIG. 4 , different from the foregoing embodiments, in this embodiment, the pixel array 400 further includes a third region Z43 whose distance to the line where the optical axis of the lens is located is greater than the second distance D42 . The pixels in the third area Z43 are third pixels P43, and one of the third pixels P43 is shown in FIG. 4 as an example. Each pixel located in the third zone Z43 has a third photosensitive area, that is, the third pixel P43 has a third photosensitive area, and the third photosensitive area is larger than the second photosensitive area. All of the first pixel P41 , the second pixel P42 and the third pixel P43 are the plurality of pixels included in the above pixel array 400 .

Please refer to FIG. 5 , which shows a schematic cross-sectional view of the pixel array 400 . In the cross-sectional structure, the straight line where the optical axis of the lens is located is the straight line where the dotted line shown in FIG. 5 is located. 4 and 5, the first distance D41 is the distance from the edge of the first zone Z41 to the straight line where the optical axis of the lens is located, and the second distance D42 is the distance from the outer edge of the second zone Z42 to the straight line where the optical axis of the lens is located.

In this embodiment, the planar shape of the pixel array 400 may also be a rectangle, and the pixel array 400 has a center 401 of a rectangle. The rectangle center 401 is also the position where the line where the optical axis of the lens is located passes through the pixel array 400 (refer to FIG. 2 and FIG. 5 in combination).

In this embodiment, the minimum side length of the rectangular pixel array 400 (the minimum side length is the length of the two short sides of the rectangle parallel to each other) can be more than 2.84mm, so as to ensure that the number of pixels in the entire pixel array 400 is relatively high (for example 5M or more). For example, specifically, the minimum side length of the pixel array 400 may be 2.84mm.

In this embodiment, considering that the minimum side length of the rectangular pixel array 400 can be more than 2.84 mm, the size range of the first distance D41 can be 0.91 mm to 1.00 mm, that is, the distance from all the first pixels P41 to the center of the rectangle 401 The distances are all less than 0.91 mm, or both are less than 1.00 mm, for example, can be specifically 1.00 mm. The first area Z41 is a circular area centered on the rectangular center 401 , and the circular area is located in the rectangular pixel array 400 .

In this embodiment, the second distance is 1.29mm˜1.42mm, that is, the distances from all the second pixels P42 to the center of the rectangle 401 are larger than the first distance D41 and less than or equal to 1.29mm˜1.42mm. The second area Z42 is an annular area centered on the rectangular center 401 , and the annular area is also located in the rectangular pixel array 400 .

In other embodiments of the present invention, it is also possible to further set the area of the first zone Z41 to be equal to the area of the second zone Z42, then at this time, the second distance D2 is equal to 1.414 times the first distance D1.

In this embodiment, the size range of the first photosensitive area may be 0.589 μm ² to 0.711 μm ² . Pixels located in the first zone Z41 receive relatively strong illuminance. Therefore, when the radius of the first zone Z41 is 0.91mm˜1.00mm (that is, when the size of the first distance D41 is 0.91mm˜1.00mm), the The above-mentioned first photosensitive area can be relatively small, that is, it can be selected from 0.589 μm ² to 0.711 μm ² , so as to ensure that the first pixel P41 has sufficient photoresponse sensitivity, and to prevent the photoresponse difference between the first pixel P41 and the second pixel P42 increase.

In this embodiment, the second photosensitive area is controlled to be 1.6 to 1.7 times the first photosensitive area. Calculated according to the cosine quadratic curve shown in Figure 2, the light quantity ratio between the first distance D41 and the center 401 is about (1/1.6) to (1/1.7), and then according to the light quantity ratio relationship, control the second The light-sensing area is about 1.6-1.7 times the first light-sensing area, so as to ensure that the second pixel P42 in the second zone Z42 can achieve a photoresponse sensitivity roughly equivalent to that of the first pixel P41 in the first zone Z41.

In this embodiment, the third photosensitive area is 1.8 to 2.0 times the second photosensitive area. Since in the pixel array 400 , the third area Z43 is an area other than the first area Z41 and the second area Z42 , the third area Z43 is located at a corner of the entire pixel array 400 . Calculated according to the cosine quadratic curve shown in Figure 2, the light quantity ratio at the second distance D42 and the first distance D41 is about (1/1.8) to (1/2.0), and then according to the relationship between the light quantity ratio, control The third light-sensing area is approximately 1.8-2.0 times the second light-sensing area, so as to ensure that the third pixel P43 in the third zone Z43 can achieve a photoresponse sensitivity roughly equivalent to that of the second pixel P42 in the second zone Z42.

It should be noted that, in other embodiments of the present invention, when the total area of the pixel array is adjusted, one-third of the minimum side length of the pixel array can also be used as the first distance, and one-third of the minimum side length of the pixel array can also be used as the first distance. The second distance is used as the second distance, and the pixel array is divided into three parts: the first area, the second area and the third area.

It should be noted that, after setting the photosensitive area of each pixel in each of the above areas, the distance from the lens (not shown) to the pixel array can be adjusted, so that the entire pixel array can achieve a better photosensitive effect.

In this embodiment, the purpose of controlling the photosensitive area in the pixel can be achieved by controlling the area of the entire pixel. Specifically, since the ratio of the area of the photosensitive area to the area of the entire pixel is relatively fixed in a pixel, when the area of the entire pixel is increased, the photosensitive area of the pixel can be correspondingly increased.

In the pixel array 400 provided in this embodiment, the pixel array 400 is divided into a first zone Z41, a second zone Z42, and a third zone Z43, and the distance between the pixels in the first zone Z41 and the straight line where the optical axis of the lens is located is less than or equal to the first Distance D41, the pixels located in the first area D41 are the first pixels P41, the distance between the pixels in the second area Z42 and the line where the optical axis of the lens is located is greater than the first distance D41 and less than or equal to the second distance D42, and they are located in the second area D42 The pixels in the third area Z43 are the second pixels P42, the distance between the pixels in the third area Z43 and the line where the optical axis of the lens is located is greater than the second distance D42, and the pixels in the third area D43 are the third pixels P43. Moreover, the first pixel P41 has a first photosensitive area, the second pixel P42 has a second photosensitive area, and the third pixel P43 has a third photosensitive area. The second photosensitive area is larger than the first photosensitive area, and the third photosensitive area is larger than the second photosensitive area. By setting the second photosensitive area larger than the first photosensitive area, and setting the third photosensitive area larger than the second photosensitive area, it is possible to adjust the photosensitivity difference between the third pixel P43, the second pixel P42 and the first pixel P41, thereby avoiding the inherent cosine four The problem of photoresponse difference caused by the power exposure law improves the uniformity of pixel photoresponse in different regions of the pixel array.

FIG. 6 shows exposure time-gray value curves of pixels in different regions of a conventional pixel array. Wherein, the division method of this embodiment is used to divide the existing pixel array to divide into the first area, the second area and the third area. At this time, the photosensitive areas of the pixels in different areas are the same. And select a pixel in the middle of each area as a representative, and make a corresponding curve. The gray value and exposure time curves corresponding to the pixels in the middle of the three areas are shown as L1, L2 and L3 in the figure respectively: the three curves include oblique lines and horizontal lines, and the oblique parts indicate that the gray value increases with time. The exposure time increases, and the horizontal line represents that the pixel has reached the saturation exposure. It can be seen from Figure 6 that due to the cosine fourth power exposure law, before reaching the saturation exposure, the slopes of the slopes of the three curves are different. Among them, the slope of the slope of L1 is obviously greater than the slope of the slope of L3, that is to say , in the case of the same photosensitive area of all pixels in the existing pixel array, the photoresponse of the first area close to the optical axis of the lens is significantly higher than the photoresponse of the third area far away from the optical axis of the lens, therefore, the photoresponse of the existing pixel array There is a more serious problem of photoresponse differences between pixels.

FIG. 7 shows the exposure time-gray value curves of the first pixel P41 , the second pixel P42 and the third pixel P43 in the pixel array 400 provided by this embodiment. It can be seen from the above that since the first pixel P41, the second pixel P42, and the third pixel P43 are set to have different light-sensing areas in this embodiment, and the second light-sensing area is larger than the first light-sensing area, the third light-sensing area is larger than the second light-sensing area area. The larger the photosensitive area of a pixel, the more photons it can receive under the same lighting conditions and exposure time, and the correspondingly more charges will be generated, which compensates for the surrounding area far away from the optical axis of the lens due to the cosine fourth power exposure law. Due to the influence of the reduction of the light quantity in the area, the pixels in different pixel areas have substantially the same photosensitivity, so the three broken lines L41 , L42 and L43 basically overlap completely. Therefore, the first pixel P41 , the second pixel P42 and the third pixel P43 basically do not have the problem of photoresponse difference, that is, the photoresponse uniformity of pixels in different regions among the pixel arrays is high.

It should be noted that, in other embodiments of the present invention, the pixel array may also be divided into four regions. Wherein, the first area whose distance to the straight line where the optical axis of the lens is located is less than or equal to the first distance. A second area whose distance to the straight line where the optical axis of the lens is located is greater than the first distance. The distance from the second area to the straight line where the optical axis of the lens is located is less than or equal to the second distance. A third area whose distance to the straight line where the optical axis of the lens is located is greater than the second distance. The distance from the third area to the straight line where the optical axis of the lens is located is less than or equal to the third distance. The fourth area whose distance to the straight line where the optical axis of the lens is located is greater than the third distance. Each pixel located in the first area has a first photosensitive area. Each pixel located in the second area has a second photosensitive area. Each pixel located in the third area has a third photosensitive area. Each pixel located in the fourth area has a fourth photosensitive area. The second photosensitive area is larger than the first photosensitive area. The third photosensitive area is larger than the second photosensitive area. The fourth photosensitive area is larger than the third photosensitive area.

It should be noted that, in other embodiments of the present invention, the pixel array may also be divided into five regions. That is, in addition to the above-mentioned fourth region, a fifth region may also be included. At this time, the distance from the fourth area to the straight line where the optical axis of the lens is located is less than or equal to the fourth distance. And the distance from the fifth area to the straight line where the optical axis of the lens is located is greater than the fourth distance.

It should be noted that, in other embodiments of the present invention, the pixel array may also be divided into more than six regions. The present invention is not limited thereto.

The embodiment of the present invention also provides a method for improving the photoresponse uniformity of the pixel array.

The method first provides a pixel array including a plurality of pixels arranged in an array. The pixel array may refer to the pixel array 300 shown in FIG. 3 or the pixel array 400 shown in FIG. 4 .

The method continues to set an area in the pixel array whose distance to the line where the optical axis of the lens is located is less than or equal to a first distance as the first area.

An area in the pixel array whose distance to the straight line where the optical axis of the lens is located is greater than the first distance is set as the second area.

Each pixel in the first area is set to have a first photosensitive area. Specifically, the size of the first photosensitive area can be adjusted by adjusting the overall area of the pixels in the first region.

Each pixel in the second area is set to have a second photosensitive area. Specifically, the size of the second photosensitive area can be adjusted by adjusting the overall area of the pixels in the second area.

Setting the second photosensitive area to be larger than the first photosensitive area to reduce the photoresponse difference between the pixels in the first area and the pixels in the second area, thereby improving the Uniformity of pixel light response.

Since the second light-sensing area is set larger than the first light-sensing area, according to the foregoing embodiments of the present specification, it can be known that the problem of differences in pixel light responses in different regions within the pixel array can be better resolved.

It should be noted that, in other embodiments of the present invention, the method may continue to set the distance from the second region to the straight line where the optical axis of the lens is located to be less than or equal to the second distance. A region in the pixel array whose distance to the straight line where the optical axis of the lens is located is greater than the second distance is set as the third region. Each pixel in the third area is set to have a third photosensitive area. The third photosensitive area is set to be larger than the second photosensitive area, so as to reduce the photoresponse difference between the pixels in the second area and the pixels in the third area, and improve the pixel light in different areas of the pixel array. uniformity of response.

It should be noted that, in other embodiments of the present invention, the method may also provide a pixel array, and the pixel array includes a plurality of pixels arranged in an array. Then set the pixel array to have N areas. Wherein, the distance from the nth area to the straight line where the optical axis of the lens is located is set to be less than or equal to the nth distance, and the distance from the (n+1)th area to the straight line where the lens optical axis is located is greater than the nth distance and less than or equal to the (n+1)th distance. Each pixel in the nth area is set to have an nth photosensitive area. Each pixel in the (n+1)th area is set to have an (n+1)th photosensitive area. And setting the (n+1) photosensitive area to be larger than the n photosensitive area, so as to reduce the photoresponse difference between the pixels in the nth region and the pixels in the (n+1)th region . Wherein, N is a natural number greater than or equal to 4, and n is a natural number from 1 to (N−1).

Although the present invention is disclosed above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, so the protection scope of the present invention should be based on the scope defined in the claims.

Claims (10)

1. a pel array, described pel array includes multiple pixels of array distribution, it is characterised in that described pel array includes:

To the distance of camera lens optical axis place straight line less than or equal to the first area of the first distance；

To the distance of camera lens optical axis place straight line more than the second area of the first distance；

The each pixel being positioned at described first area has the first photosensitive area；

The each pixel being positioned at described second area has the second photosensitive area；

Described second photosensitive area is more than described first photosensitive area.

2. pel array as claimed in claim 1, it is characterised in that the minimum length of side of described pel array is more than 2.84mm, and the magnitude range of described first distance is 1.29mm～1.42mm.

3. pel array as claimed in claim 2, it is characterised in that the magnitude range of described first photosensitive area is 0.589 μm²～0.711 μm², described second photosensitive area is 1.8 times～2.0 times of described first photosensitive area.

4. pel array as claimed in claim 1, it is characterised in that described second area is to the distance of camera lens optical axis place straight line less than or equal to second distance, and described pel array also includes:

To the distance of camera lens optical axis place straight line more than the 3rd region of second distance；

The each pixel being positioned at described 3rd region has the 3rd photosensitive area；

Described 3rd photosensitive area is more than described second photosensitive area.

5. pel array as claimed in claim 4, it is characterised in that the minimum length of side of described pel array is more than 2.84mm, and described first distance is 0.91mm～1.00mm, and described second distance is 1.29mm～1.42mm.

6. pel array as claimed in claim 5, it is characterised in that the magnitude range of described first photosensitive area is 0.589 μm²～0.711 μm², described second photosensitive area is 1.6 times～1.7 times of described first photosensitive area, and described 3rd photosensitive area is 1.8 times～2.0 times of described second photosensitive area.

7. pel array as claimed in claim 4, it is characterised in that described 3rd region is to the distance of camera lens optical axis place straight line less than or equal to the 3rd distance, and described pel array also includes:

To the distance of camera lens optical axis place straight line more than the 4th region of the 3rd distance；

The each pixel being positioned at described 4th region has the 4th photosensitive area；

Described 4th photosensitive area is more than described 3rd photosensitive area.

8. pel array as claimed in claim 7, it is characterised in that described 4th region is to the distance of camera lens optical axis place straight line less than or equal to the 4th distance, and described pel array also includes:

To the distance of camera lens optical axis place straight line more than the 5th region of the 4th distance；

The each pixel being positioned at described 5th region has the 5th photosensitive area；

Described 5th photosensitive area is more than described 4th photosensitive area.

9. the method for the photoresponse uniformity improving pel array, it is characterised in that described method includes:

Thering is provided pel array, described pel array includes multiple pixels of array arrangement；

Arranging in described pel array to the distance of camera lens optical axis place straight line less than or equal to the region of the first distance is first area；

Arranging in described pel array to the distance of camera lens optical axis place straight line more than the region of the first distance is second area；

The each pixel arranged in described first area has the first photosensitive area；

The each pixel arranged in described second area has the second photosensitive area；

Described second photosensitive area is set more than described first photosensitive area, to reduce the photoresponse difference between the pixel in described first area and the pixel in described second area.

10. the method for the photoresponse uniformity improving pel array as claimed in claim 9, it is characterised in that also include:

The described second area distance to camera lens optical axis place straight line is set less than or equal to second distance；

Arranging in described pel array to the distance of camera lens optical axis place straight line more than the region of second distance is the 3rd region；

The each pixel arranged in described 3rd region has the 3rd photosensitive area；

Described 3rd photosensitive area is set more than described second photosensitive area, to reduce the photoresponse difference between the pixel in described second area and the pixel in described 3rd region.