Image sensor, focusing control method, and electronic device

1. A method of focusing control for an image sensor, the image sensor comprising:

a photosensitive cell array, comprising one or more focusing photosensitive cells and a plurality of non-focusing photosensitive cells; each of the focusing photosensitive cells comprising a plurality of photosensitive pixels;

a filtering cell array, disposed above the photosensitive cell array; and

a micro-lens array, located above the filtering cell array, and comprising one or more first micro-lenses and a plurality of second micro-lenses; wherein each of the focusing photosensitive cells is covered by a corresponding one of the first micro-lenses, and each of the non-focusing photosensitive cells is covered by N*N of the second micro-lenses; wherein N is a positive integer; and

the method comprising:

controlling the photosensitive cell array to enter a focusing mode;

reading output values of a part of the photosensitive pixels in each of the focusing photosensitive cells as first output values;

reading output values of the remaining part of the photosensitive pixels in each of the focusing photosensitive cells as second output values; and

performing focusing control according to the first output values and the second output values, comprising:

generating, according to the first output values, a first phase value; wherein the first phase value is a sum of the first output values;

generating, according to the second output values, a second phase value; wherein the second phase value is a sum of the second output values; and

performing the focusing control according to the first phase value and the second phase value.

2. The method of claim 1 , wherein the image sensor is used in an electronic device, and the electronic device comprises a lens; and

performing the focusing control according to the first phase value and the second phase value comprises:

acquiring phase difference information by using the first phase value and the second phase value;

converting the phase difference information into focus distance information; and

adjusting, according to the focus distance information, a position of the lens.

3. The method of claim 1 , wherein the micro-lens array has a horizontal centerline and a vertical centerline; a number of the first micro-lenses is two or more, and the two or more first micro-lenses comprise:

a first group of first micro-lenses, disposed along the horizontal centerline; and

a second group of first micro-lenses, disposed along the vertical centerline.

4. The method of claim 3 , wherein the micro-lens array has four edges, and the two or more first micro-lenses further comprise:

a third group of first micro-lenses, disposed on the four edges.

5. The method of claim 4 , wherein the first group of first micro-lenses are arranged in a first density; the second group of first micro-lenses are arranged in a second density, and the third group of first micro-lenses are arranged in a third density; and the first density and the second density are greater than the third density.

6. The method of claim 4 , wherein the four edges are arranged to form a rectangle, each of the leftmost first micro-lenses and the rightmost first micro-lenses one of the first group of first micro-lenses along the horizontal centerline is located on one of the four edges, and each of the top first micro-lenses and the bottom first micro-lenses of the second group of first micro-lenses along the vertical centerline is located on one of the four edges;

the third group of first micro-lenses comprises four first micro-lenses disposed on four corners of the rectangle, and each of the leftmost first micro-lenses, the rightmost first micro-lenses, the top first micro-lenses, and the bottom first micro-lenses is disposed on a straight line defined by adjacent two of the four first micro-lenses.

7. The method of claim 1 , wherein each of the focusing photosensitive cells and the non-focusing photosensitive cells comprise N*N photosensitive pixels, and the method further comprises:

controlling the photosensitive cell array to enter an imaging mode;

controlling to expose the focusing photosensitive cells and the non-focusing photosensitive cells, and reading output values of the photosensitive pixels of the focusing photosensitive cells and output values of the photosensitive pixels of the non-focusing photosensitive cells; and

acquiring a first pixel value of each of the focusing photosensitive cells by adding the output values of the N*N photosensitive pixels in the same focusing photosensitive cell, acquiring a second pixel value of each of the non-focusing photosensitive cells by adding the output values of the N*N photosensitive pixels in the same non-focusing photosensitive cell, and generating a merged image by the first pixel value and the second pixel value.

8. An image sensor, comprising:

a photosensitive cell array, comprising one or more focusing photosensitive cells and a plurality of non-focusing photosensitive cells; each of the focusing photosensitive cells comprising a plurality of photosensitive pixels;

a filtering cell array, disposed above the photosensitive cell array;

a micro-lens array, located above the filtering cell array, and comprising one or more first micro-lenses and a plurality of second micro-lenses; wherein each of the focusing photosensitive cells is covered by a corresponding one of the first micro-lenses, and each of the non-focusing photosensitive cells is covered by N*N of the second micro-lenses; wherein N is a positive integer; and

a controller, coupled to the photosensitive cell array and configured to:

control the photosensitive cell array to enter a focusing mode;

read output values of a part of the photosensitive pixels in each of the focusing photosensitive cells as first output values;

read output values of the remaining part of the photosensitive pixels in each of the focusing photosensitive cells as second output values; and

perform focusing control according to the first output values and the second output values;

wherein the micro-lens array has a horizontal centerline, a vertical centerline, and four edges, the number of the first micro-lenses is two or more, and the two or more first micro-lenses comprises:

a first group of first micro-lenses, disposed along the horizontal centerline;

a second group of first micro-lenses, disposed along the vertical centerline; and

a third group of first micro-lenses, disposed on the four edges;

wherein the first group of first micro-lenses are arranged in a first density, the second group of first micro-lenses are arranged in a second density, the third group of first micro-lenses are arranged in a third density, and the first density and the second density are greater than the third density.

9. The image sensor of claim 8 , wherein each of the focusing photosensitive cells and the non-focusing photosensitive cells comprises N*N photosensitive pixels.

10. The image sensor of claim 8 , wherein the image sensor is used in an electronic device, and the electronic device comprises a lens; and

the controller is configured to perform focusing control according to the first output values and the second output values by:

generating, according to the first output values, a first phase value; wherein the first phase value is a sum of the first output values;

generating, according to the second output values, a second phase value; wherein the second phase value is a sum of the second output values;

acquiring phase difference information by using the first phase value and the second phase value;

converting the phase difference information into focus distance information; and

adjusting, according to the focus distance information, a position of the lens.

11. The image sensor of claim 8 , wherein the controller is further configured to:

control the photosensitive cell array to enter an imaging mode;

control to expose the focusing photosensitive cells and the non-focusing photosensitive cells, and read output values of the photosensitive pixels of the focusing photosensitive cells and output values of the photosensitive pixels of the non-focusing photosensitive cells; and

acquire a first pixel value of each of the focusing photosensitive cells by adding the output values of the N*N photosensitive pixels in the same focusing photosensitive cell, acquire a second pixel value of each of the non-focusing photosensitive cells by adding the output values of the N*N photosensitive pixels in the same non-focusing photosensitive cell, and generating a merged image by the first pixel value and the second pixel value.

12. The image sensor of claim 8 , wherein the filtering cell array comprises a plurality of filtering cells; and each of the filtering cells is disposed correspondingly to one of the focusing photosensitive cells or one of the non-focusing photosensitive cells.

13. The image sensor of claim 8 , wherein the four edges are arranged to form a rectangle, each of the leftmost first micro-lenses and the rightmost first micro-lenses one of the first group of first micro-lenses along the horizontal centerline is located on one of the four edges, and each of the top first micro-lenses and the bottom first micro-lenses of the second group of first micro-lenses along the vertical centerline is located on one of the four edges;

the third group of first micro-lenses comprises four first micro-lenses disposed on four corners of the rectangle, and each of the leftmost first micro-lenses, the rightmost first micro-lenses, the top first micro-lenses, and the bottom first micro-lenses is disposed on a straight line defined by adjacent two of the four first micro-lenses.

14. An electronic device, comprising:

a housing;

an image sensor, received in the housing and comprising:

a photosensitive cell array, comprising one or more focusing photosensitive cells and a plurality of non-focusing photosensitive cells; each of the focusing photosensitive cells and the non-focusing photosensitive cells comprising N*N photosensitive pixels;

wherein N is a positive integer;

a filtering cell array, disposed above the photosensitive cell array; and

a micro-lens array, located above the filtering cell array, and comprising one or more first micro-lenses and a plurality of second micro-lenses; wherein each of the first micro-lenses is disposed correspondingly to and covering N*N photosensitive pixels in the corresponding focusing photosensitive cell; each of the second micro-lenses is disposed correspondingly to and covering one photosensitive pixel in the corresponding non-focusing photosensitive cell;

a non-transitory memory, received in the housing and configured to store a executable program code; and

a processor, received in the housing, configured to read the executable program code stored in the non-transitory memory, and run a program corresponding to the executable program code to:

control the photosensitive cell array to enter a focusing mode;

read output values of a part of the plurality of photosensitive pixels in each of the focusing photosensitive cells as first output values;

read output values of the remaining part of the plurality of photosensitive pixels in each of the focusing photosensitive cells as second output values;

perform focusing control according to the first output values and the second output values;

control the photosensitive cell array to enter an imaging mode;

control to expose the focusing photosensitive cells and the non-focusing photosensitive cells, and read output values of the photosensitive pixels of the focusing photosensitive cells and output values of the photosensitive pixels of the non-focusing photosensitive cells; and

acquire a first pixel value of each of the focusing photosensitive cells by adding the output values of the N*N photosensitive pixels in the same focusing photosensitive cell, acquire a second pixel value of each of the non-focusing photosensitive cells by adding the output values of the N*N photosensitive pixels in the same non-focusing photosensitive cell, and generate a merged image by the first pixel value and the second pixel value.

15. The electronic device of claim 14 , further comprising a lens; wherein the processor is configured to perform focusing control according to the first output values and the second output values by:

generating, according to the first output values, a first phase value; wherein the first phase value is a sum of the first output values;

generating, according to the second output values, a second phase value; wherein the second phase value is a sum of the second output values;

acquiring phase difference information by using the first phase value and the second phase value;

converting the phase difference information into focus distance information; and

adjusting, according to the focus distance information, a position of the lens.

16. The electronic device of claim 14 , wherein the micro-lens array has a horizontal centerline, a vertical centerline, and four edges; the number of the first micro-lenses is two or more, and the two or more first micro-lenses comprises:

a first group of first micro-lenses, disposed along the horizontal centerline;

a second group of first micro-lenses, disposed along the vertical centerline; and

a third group of first micro-lenses, disposed on the four edges;

the first group of first micro-lenses are arranged in a first density; the second group of first micro-lenses are arranged in a second density, and the third group of first micro-lenses are arranged in a third density; and the first density and the second density are greater than the third density.

17. The electronic device of claim 16 , wherein the four edges are arranged to form a rectangle, each of the leftmost first micro-lenses and the rightmost first micro-lenses one of the first group of first micro-lenses along the horizontal centerline is located on one of the four edges, and each of the top first micro-lenses and the bottom first micro-lenses of the second group of first micro-lenses along the vertical centerline is located on one of the four edges;

the third group of first micro-lenses comprises four first micro-lenses disposed on four corners of the rectangle, and each of the leftmost first micro-lenses, the rightmost first micro-lenses, the top first micro-lenses, and the bottom first micro-lenses is disposed on a straight line defined by adjacent two of the four first micro-lenses.

18. The electronic device of claim 14 , wherein the filtering cell array comprises a plurality of filtering cells; and each of the filtering cells is disposed correspondingly to one of the focusing photosensitive cells or one of the non-focusing photosensitive cells.