The application is a divisional application of a parent application named 'an image sensor' with the application number of 201910230735.6 and the application date of 2019, 3 and 26.
Detailed Description
In order to explain technical contents, objects and effects of the present invention in detail, the following detailed description is given with reference to the accompanying drawings in conjunction with the embodiments.
The most key concept of the invention is as follows: the first area is internally provided with color filter elements and white filter units which are distributed in an array mode, and the number ratio of the color filter elements to the white filter units is greater than or equal to 3: 1; the second area and the third area are respectively provided with a color filter element and a white filter unit, and the ratio of the number of the filter units included in the color filter element in the second area to the number of the white filter units in the second area is less than or equal to 1: 3; the ratio of the number of white filter cells in the third area to the number of filter cells included in the color filter element in the third area is greater than 85: 15.
referring to fig. 1 to 7, the present invention provides a high-sensitivity image sensor, which includes a square first region, a square second region and a square third region; the outer edge of the first area is connected with the inner edge of the second area, and the outer edge of the second area is connected with the inner edge of the third area;
the color filter elements and the white filter units are arranged in the first area in an array mode, the ratio of the number of the filter units included in the color filter elements in the first area to the number of the white filter units in the first area is greater than or equal to 3: 1;
the second area and the third area are respectively provided with a color filter element and a white filter unit, and the ratio of the number of the filter units included in the color filter element in the second area to the number of the white filter units in the second area is less than or equal to 1: 3; the ratio of the number of white filter cells in the third area to the number of filter cells included in the color filter element in the third area is greater than 85: 15;
the color filter element comprises a red filter unit, a green filter unit and a blue filter unit.
In a human eye vision system evolved for a long time, the problems existing in the background can be well solved by means of special human eye photosensitive structure distribution, and meanwhile, development of a higher-performance image sensor aiming at different fields also has important significance, such as development of an intelligent robot vision system and the like. In a typical human eye structure, there are two types of photoreceptor cells: cone and rod cells. Wherein, cone cells are responsible for perceiving highlight and color, about 600 ten thousand are mainly distributed in the central concave part of the human eye structure; the rods are responsible for sensing low light and black and white, up to 12000 million, and are located mainly at the edge of the central fovea, and their distribution is shown in fig. 3. The total proportion of the number of RGB and the number of W of the image sensor of the present invention is set according to the proportion of the number of RGB color filter units and the number of W white filter units of human eyes (600 ten thousand/12000 ten thousand is 5%), in fig. 3, the cone cells in the middle are distributed more and the rod cells in the periphery are distributed more, and according to this characteristic, the cone cells can be equivalent to red (R), green (G) and blue (B) filter units, and the rod cells can be regarded as white (W) filter units, that is, the proportion of the color filter units in the middle area is large and the proportion of the white filter units in the peripheral area is large. The relative spectral sensitivity of color cones in human vision is shown in fig. 4.
The english interpretation in fig. 3 and 4 is as follows:
numberofrechtorsper mm 2: the number of photoreceptor cells;
anglefm fovea: the angle of the photoreceptor cells (rod and cone) relative to the fovea;
fovea: the fovea centralis;
blind spot: a human eye blind spot;
normalized absorbance (Normalized);
wavelet: a wavelength;
blue cons: blue cone cells;
green cons: green cone cells;
red wires: red cone cells;
rods: a rod cell;
short: short wave length;
medium: a medium wave wavelength;
and (4) Long: a long wavelength;
cons: a cone cell;
rods: a rod cell;
as can be seen from the above description, the image sensor with high sensitivity provided by the present invention includes a red filter unit, a green filter unit, a blue filter unit, and a white filter unit in a color filter element, and the color filter units are distributed more in a central area (a first area) of the image sensor, the white filter units are distributed relatively less, and the ratio of the two is greater than 3: 1, approaching the perception ratio of the central area of human eyes to (strong light and color) and (weak light and black and white), and respectively arranging a second area and a third area outside the central area to enable the number of white filter units to be more than that of color filter units, wherein the ratio of the number of filter units included by the color filter element in the second area to the number of white filter units in the second area is less than or equal to 1: 3, the ratio of the number of white filter cells in the third area to the number of filter cells included in the color filter element in the third area is greater than 85: 15; the human eye color image sensing proportion is close to the perception proportion of the areas outside the central area of the human eye and the edge areas to strong light and color) and (weak light and black and white), so that the invention can effectively realize that a high-resolution and high-sensitivity color image close to that seen by the human eye can be obtained under the condition of large light intensity or small light intensity.
Further, the first region includes a plurality of first filter blocks, each of which includes a red filter unit, a green filter unit, a blue filter unit, and a white filter unit; the four filtering units of each first filtering block are distributed in a square matrix of two rows and two columns.
As can be seen from the above description, the arrangement makes the central region of the image sensor sense both the color light and the weak light.
Furthermore, the second region includes a plurality of second filter blocks, each second filter block is composed of four first sub-filter blocks, the first sub-filter block includes a red filter unit and three white filter units, the second first sub-filter block includes a green filter unit and three white filter units, the third first sub-filter block includes a green filter unit and three white filter units, and the fourth first sub-filter block includes a blue filter unit and three white filter units; the four filter units of each first sub-filter block are distributed in a square matrix of two rows and two columns.
Further, the third area includes a plurality of third filter blocks, each of which includes one red filter unit, two green filter units, one blue filter unit, and sixty white filter units; sixty-four filtering units of each third filtering block are distributed in a square matrix of eight rows and eight columns.
From the above description, it can be known that, through the above structure, the red, green and blue filter units in the central area of the photosensitive device are distributed more, the white filter units are distributed relatively less, and the white filter units in the area of the photosensitive device far from the center are distributed more, and the red, green and blue filter units are distributed relatively less, so that it is effectively realized that the four first sub-filters which can obtain a high-resolution and high-sensitivity color image close to that seen by human eyes form a large unit to represent a color output unit, and the distribution of cone cells and rod cells of human eyes is similar to that seen by human eyes, and the proportion of the number of colors is smaller as going to the periphery.
Further, the first region, the second region and the third region are connected to form a square region;
the side length of the first area is 1/3 of the side length of the square area; the distance from the outer edge of the second area to the inner edge of the second area is 1/6 of the side length of the square area; the distance from the outer edge of the third region to the inner edge of the third region is 1/6 the side length of the square region.
From the above description, it can be known that the proportion simulates the distribution of cone cells and rod cells of human eyes, and effectively realizes that a high-resolution and high-sensitivity color image close to that seen by human eyes can be obtained under the conditions of bright field or extremely weak light.
Further, the third area includes a plurality of fourth filter blocks, each fourth filter block is composed of four second sub-filter blocks, the first second sub-filter block includes a red filter unit and eight white filter units, the second sub-filter block includes a green filter unit and eight white filter units, the third second sub-filter block includes a green filter unit and eight white filter units, and the fourth second sub-filter block includes a blue filter unit and eight white filter units; the nine filtering units of each second filtering block are distributed in a square matrix of three rows and three columns.
Further, the first region, the second region and the third region are connected to form a square region;
the side length of the first area is 1/2 of the side length of the square area; the distance from the outer edge of the second area to the inner edge of the second area is 1/8 of the side length of the square area; the distance from the outer edge of the third region to the inner edge of the third region is 1/8 the side length of the square region.
From the above description, it can be known that the proportion simulates the distribution of cone cells and rod cells of human eyes, and effectively realizes that a high-resolution and high-sensitivity color image close to that seen by human eyes can be obtained under the conditions of bright field or extremely weak light.
Further, the first area comprises a square first sub-area and a square second sub-area, the second area comprises a square third sub-area and a square fourth sub-area, the outer edge of the first sub-area is connected with the inner edge of the second sub-area, the outer edge of the second sub-area is connected with the inner edge of the third sub-area, and the outer edge of the third sub-area is connected with the inner edge of the fourth sub-area; the outer edge of the fourth sub-region is connected with the inner edge of the third region.
Furthermore, the first sub-area comprises a plurality of fifth filter blocks, each fifth filter block comprises a red filter unit, two green filter units and a blue filter unit, and four filter units of each fifth filter block are distributed in a square matrix of two rows and two columns;
the second subregion includes a plurality of sixth filter blocks, and each sixth filter block all includes a red filter unit, a green filter unit, a blue filter unit and a white filter unit, and four filter units of each sixth filter block all are the square matrix distribution of two rows and two columns.
Furthermore, the third sub-area includes a plurality of seventh filter blocks, each of the seventh filter blocks is composed of four third sub-filter blocks, the first third sub-filter block includes a red filter unit, a green filter unit and two white filter units, the second third sub-filter block includes a blue filter unit, a green filter unit and two white filter units, the third first sub-filter block includes a blue filter unit, a green filter unit and two white filter units, and the fourth first sub-filter block includes a red filter unit, a green filter unit and two white filter units; the four filtering units of each third sub-filtering block are distributed in a square matrix of two rows and two columns;
the fourth sub-area comprises a plurality of eighth filter blocks, each eighth filter block consists of four fourth sub-filter blocks, the first fourth sub-filter block comprises a red filter unit and three white filter units, the second fourth sub-filter block comprises a green filter unit and three white filter units, the third fourth sub-filter block comprises a green filter unit and three white filter units, and the fourth sub-filter block comprises a blue filter unit and three white filter units; the four filtering units of each fourth sub-filtering block are distributed in a square matrix of two rows and two columns;
the first sub-area, the second sub-area, the third sub-area, the fourth sub-area and the third area are connected to form a square area;
the side length of the first sub-area is 1/5 of the side length of the square area; the distance from the outer edge of the second sub-area to the inner edge of the second sub-area is 1/10 of the side length of the square area; the distance from the outer edge of the third sub-area to the inner edge of the third sub-area is 1/10 of the side length of the square area; the distance from the outer edge of the fourth subregion to the inner edge of the fourth subregion is 1/10 of the side length of the square region; the distance from the outer edge of the third region to the inner edge of the third region is 1/10 the side length of the square region.
From the above description, it can be known that, through the above structure, the red, green and blue filter units in the central area of the photosensitive device are distributed more, the white filter units are distributed relatively less, and the white filter units in the area of the photosensitive device far from the center are distributed more, and the red, green and blue filter units are distributed relatively less, so that it is effectively realized that the four first sub-filters which can obtain a high-resolution and high-sensitivity color image close to that seen by human eyes form a large unit to represent a color output unit, and the distribution of cone cells and rod cells of human eyes is similar to that seen by human eyes, and the proportion of the number of colors is smaller as going to the periphery. The proportion simulates the distribution of cone cells and rod cells of human eyes, and the high-resolution and high-sensitivity color images which are close to those seen by the human eyes can be effectively obtained in bright fields or under the condition of extremely weak light.
The first embodiment of the invention is as follows:
the invention provides an image sensor, which comprises a square first area, a square-shaped second area and a square-shaped third area; the outer edge of the first area is connected with the inner edge of the second area, and the outer edge of the second area is connected with the inner edge of the third area;
the color filter elements and the white filter units are arranged in the first area in an array mode, the ratio of the number of the filter units included in the color filter elements in the first area to the number of the white filter units (W) in the first area is greater than or equal to 3: 1;
the second area and the third area are respectively provided with a color filter element and a white filter unit, and the ratio of the number of the filter units included in the color filter element in the second area to the number of the white filter units in the second area is less than or equal to 1: 3; the ratio of the number of white filter cells in the third area to the number of filter cells included in the color filter element in the third area is greater than 85: 15;
wherein the color filter element includes a red filter unit (R), a green filter unit (G), and a blue filter unit (B).
Referring to fig. 5, a second embodiment of the present invention is:
the second embodiment of the present invention is different from the first embodiment in that the first region includes a square first sub-region and a square second sub-region, the second region includes a square third sub-region and a square fourth sub-region, an outer edge of the first sub-region is connected to an inner edge of the second sub-region, an outer edge of the second sub-region is connected to an inner edge of the third sub-region, and an outer edge of the third sub-region is connected to an inner edge of the fourth sub-region; the outer edge of the fourth sub-area is connected with the inner edge of the third area;
the first sub-area comprises a plurality of fifth filtering blocks, each fifth filtering block comprises a red filtering unit, two green filtering units and a blue filtering unit, and four filtering units of each fifth filtering block are distributed in a square matrix of two rows and two columns;
the second subregion includes a plurality of sixth filter blocks, and each sixth filter block all includes a red filter unit, a green filter unit, a blue filter unit and a white filter unit, and four filter units of each sixth filter block all are the square matrix distribution of two rows and two columns.
The third sub-area comprises a plurality of seventh filtering blocks, each seventh filtering block consists of four third sub-filtering blocks, the first third sub-filtering block comprises a red filtering unit, a green filtering unit and two white filtering units, the second third sub-filtering block comprises a blue filtering unit, a green filtering unit and two white filtering units, the third first sub-filtering block comprises a blue filtering unit, a green filtering unit and two white filtering units, and the fourth first sub-filtering block comprises a red filtering unit, a green filtering unit and two white filtering units; the four filtering units of each third sub-filtering block are distributed in a square matrix of two rows and two columns; each seventh filtering block comprises sixteen filtering units, namely a square matrix with four rows and four columns;
the fourth sub-area comprises a plurality of eighth filter blocks, each eighth filter block consists of four fourth sub-filter blocks, the first fourth sub-filter block comprises a red filter unit and three white filter units, the second fourth sub-filter block comprises a green filter unit and three white filter units, the third fourth sub-filter block comprises a green filter unit and three white filter units, and the fourth sub-filter block comprises a blue filter unit and three white filter units; the four filtering units of each fourth sub-filtering block are distributed in a square matrix of two rows and two columns; each eighth filtering block comprises sixteen filtering units, namely a square matrix with four rows and four columns;
the third area comprises a plurality of third filtering blocks, and each third filtering block comprises a red filtering unit, two green filtering units, a blue filtering unit and sixty white filtering units; sixty-four filtering units of each third filtering block are distributed in a matrix of eight rows and eight columns;
the first sub-area, the second sub-area, the third sub-area, the fourth sub-area and the third area are connected to form a square area; the side length of the first sub-area is 1/5 of the side length of the square area; the distance from the outer edge of the second sub-area to the inner edge of the second sub-area is 1/10 of the side length of the square area; the distance from the outer edge of the third sub-area to the inner edge of the third sub-area is 1/10 of the side length of the square area; the distance from the outer edge of the fourth subregion to the inner edge of the fourth subregion is 1/10 of the side length of the square region; the distance from the outer edge of the third region to the inner edge of the third region is 1/10 the side length of the square region.
Wherein, the first sub-region corresponds to the Zone0 in fig. 5, the second sub-region corresponds to the Zone1 in fig. 5, the third sub-region corresponds to the Zone2 in fig. 5, the fourth sub-region corresponds to the Zone3 in fig. 5, and a third region, that is, the Zone4 in fig. 5 (not shown, N is 4) is arranged at the periphery of the fourth sub-region; the region may be further set outside the third region as necessary.
Referring to fig. 6, a third embodiment of the present invention is:
the third embodiment of the present invention is different from the first embodiment in that the first region includes a plurality of first filter blocks, each of which includes a red filter unit, a green filter unit, a blue filter unit, and a white filter unit; the four filtering units of each first filtering block are distributed in a square matrix of two rows and two columns;
the second area comprises a plurality of second filter blocks, each second filter block consists of four first sub filter blocks, the first sub filter block comprises a red filter unit and three white filter units, the second first sub filter block comprises a green filter unit and three white filter units, the third first sub filter block comprises a green filter unit and three white filter units, and the fourth first sub filter block comprises a blue filter unit and three white filter units; the four filter units of each first sub-filter block are distributed in a square matrix of two rows and two columns.
The third area comprises a plurality of third filtering blocks, and each third filtering block comprises a red filtering unit, two green filtering units, a blue filtering unit and sixty white filtering units; sixty-four filtering units of each third filtering block are distributed in a matrix of eight rows and eight columns;
the first region, the second region and the third region are connected to form a square region; the side length of the first area is 1/3 of the side length of the square area; the distance from the outer edge of the second area to the inner edge of the second area is 1/6 of the side length of the square area; the distance from the outer edge of the third region to the inner edge of the third region is 1/6 the side length of the square region.
The first area corresponds to the Zone0 in fig. 6, the second area corresponds to the Zone1 in fig. 6, and the third area corresponds to the Zone2 in fig. 6.
Referring to fig. 7, a fourth embodiment of the present invention is:
the fourth embodiment of the present invention is different from the first embodiment in that the first region includes a plurality of first filter blocks, each of which includes a red filter unit, a green filter unit, a blue filter unit, and a white filter unit; the four filtering units of each first filtering block are distributed in a square matrix of two rows and two columns.
The second area comprises a plurality of second filter blocks, each second filter block consists of four first sub filter blocks, the first sub filter block comprises a red filter unit and three white filter units, the second first sub filter block comprises a green filter unit and three white filter units, the third first sub filter block comprises a green filter unit and three white filter units, and the fourth first sub filter block comprises a blue filter unit and three white filter units; the four filtering units of each first sub-filtering block are distributed in a square matrix of two rows and two columns;
the third area comprises a plurality of fourth filter blocks, each fourth filter block consists of four second sub-filter blocks, the first second sub-filter block comprises a red filter unit and eight white filter units, the second sub-filter block comprises a green filter unit and eight white filter units, the third second sub-filter block comprises a green filter unit and eight white filter units, and the fourth second sub-filter block comprises a blue filter unit and eight white filter units; nine filtering units of each second filtering block are distributed in a square matrix of three rows and three columns;
the first region, the second region and the third region are connected to form a square region; the side length of the first area is 1/2 of the side length of the square area; the distance from the outer edge of the second area to the inner edge of the second area is 1/8 of the side length of the square area; the distance from the outer edge of the third region to the inner edge of the third region is 1/8 the side length of the square region.
The first area corresponds to the Zone0 in fig. 7, the second area corresponds to the Zone1 in fig. 7, and the third area corresponds to the Zone2 in fig. 7.
Example five of the present invention:
the invention also provides an imaging method for the image sensor, which comprises the following steps:
dividing the color image sensor into n sub-areas, and calculating a red pixel photosensitive value Ri, a green pixel photosensitive value Gi, a blue pixel photosensitive value Bi and an all-pass pixel photosensitive value Wi of each sub-area;
wherein, R, G, B and W pixels in each sub-region have different light sensing, and corresponding RGB gray scale values, namely the above-mentioned light sensing values, can be obtained;
superposing the Ri, Gi and Bi photosensitive values of each sub-region pixel to obtain a color channel image of each sub-region; the Wi value is used as a brightness channel image;
superposing the color channel image and the brightness channel image of each subregion to obtain a final image of each subregion; and then splicing the final images of each sub-area to obtain a final color image of the whole color image sensor.
In summary, the present invention provides a high-sensitivity image sensor, which conforms to the characteristics of the human visual system, in the second embodiment, the third embodiment and the fourth embodiment, the white filter of the third region occupies a ratio of 93.75%, 93.75% and 88.8% at the maximum respectively, which is close to 95% of human eye rod cells, but since it is the maximum value, this ratio may be higher, for example, the arrangement ratio of the outermost layer of the image sensor may be that in every 6 × 4 filter cell in fig. 8A, there is one color filter, twenty-three white filters, and the ratio of white cells is 95.85%. The 6 × 4 may also be 4 × 6, or other division such as 12 × 12 in fig. 8B, with a white proportion of 99%.
The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent changes made by using the contents of the present specification and the drawings, or applied directly or indirectly to other related technical fields, are included in the scope of the present invention.