Multispectral sensing system and method

1. A multispectral sensing device, comprising:

an array of pixel units; and

a processing circuit, wherein:

each of the pixel units comprises four pixels in a two by two configuration;

each of the pixels comprises a plurality of sub-pixels;

each of the pixel units includes at least one pixel that includes at least two sub-pixels configured to detect light of different wavelengths;

each of the sub-pixels in the at least one pixel of the pixel units comprises a tunable optical filter; and

the processing circuit is coupled to each optical filter and configured to tune a wavelength sensing range of each tunable optical filter.

2. The multispectral sensing device of claim 1 , wherein the array is a Bayer-pattern array.

3. The multispectral sensing device of claim 1 , wherein:

each of the pixels comprises four sub-pixels;

each of the pixel units comprises sixteen sub-pixels; and

the sixteen sub-pixels are configured to detect light of different wavelengths or wavelength bands.

4. The multispectral sensing device of claim 1 , wherein:

each of the sub-pixels comprises a .mu.lens, and a photodiode;

the .mu.lens is disposed above the optical filter;

the photodiode is disposed below the optical filter;

the .mu.lens is configured to direct impinging light to pass through the optical filter; and

the photodiode is configured to detect the light passed through the optical filter.

5. The multispectral sensing device of claim 4 , further comprising:

a processing circuit coupled to the photodiode of each of the sub-pixels, wherein the processing circuit is configured to obtain a total reading of all photodiode readings in each pixel; and

output the total reading as the pixel's reading.

6. The multispectral sensing device of claim 4 , further comprising:

a processing circuit coupled to the photodiode of each of the sub-pixels, wherein the processing circuit is configured to obtain one photodiode's reading from all photodiodes in each pixel;

determine the pixel's reading based on the obtained reading; and

output the determined reading as the pixel's reading.

7. The multispectral sensing device of claim 1 , wherein, in each pixel:

three of the four sub-pixels are configured to detect visible light; and

the other sub-pixel of the four sub-pixels is configured to detect infrared light.

8. The multispectral sensing device of claim 7 , wherein:

the three sub-pixels are configured to detect red, blue, and green light respectively; and

the other sub-pixel is configured to detect near infrared light.

9. A multispectral sensing device, comprising:

an array of pixels; and

a processing circuit, wherein:

each of the pixels comprises a plurality of sub-pixels;

at least two of the sub-pixels in one pixel of the array are configured to detect light of different wavelengths;

each of the sub-pixels in the one pixel of the array comprises a tunable optical filter; and

the processing circuit is coupled to each optical filter and configured to tune a wavelength sensing range of each tunable optical filter.

10. The multispectral sensing device of claim 9 , wherein the array is a Bayer-pattern array.

11. The multispectral sensing device of claim 10 , wherein the plurality of sub-pixels are configured to detect light of various wavelengths or wavelength bands different from each other and from sub-pixels of any of eight closest neighboring pixels.

12. The multispectral sensing device of claim 9 , wherein:

each of the sub-pixels comprises a .mu.lens, and a photodiode;

the .mu.lens is disposed above the optical filter;

the photodiode is disposed below the optical filter;

the .mu.lens is configured to direct impinging light to pass through the optical filter; and

the photodiode is configured to detect the light passed through the optical filter.

13. The multispectral sensing device of claim 12 , further comprising:

a processing circuit coupled to the photodiode of each of the sub-pixels, wherein the processing circuit is configured to obtain a total reading of all photodiode readings in each pixel; and

output the total readings as the pixel's reading.

14. The multispectral sensing device of claim 12 , further comprising:

a processing circuit coupled to the photodiode of each of the sub-pixels, wherein the processing circuit is configured to obtain one photodiode's reading from all photodiodes in each pixel;

determine the pixel's reading based on the obtained reading; and

output the determined reading as the pixel's reading.

15. The multispectral sensing device of claim 9 , wherein, in each pixel:

the plurality of sub-pixels comprise four sub-pixels;

three of the four sub-pixels are configured to detect visible light; and

the other sub-pixel of the four sub-pixels is configured to detect infrared light.

16. The multispectral sensing device of claim 15 , wherein:

the three sub-pixels are configured to detect red, blue, and green light respectively; and

the other sub-pixel is configured to detect near infrared light.

17. A multispectral sensing system, comprising:

a Bayer-pattern array of pixels, each pixel comprising a plurality of sub-pixels;

a processing circuit coupled to each of the sub-pixels and configured to tune a detection wavelength band of the sub-pixel, causing the sub-pixels to be switchable between detecting light of the same and different wavelength bands;

each of the sub-pixels in the pixels comprises a tunable optical filter; and

the detection wavelength band of each of the sub-pixels in the pixels is tunable through tuning a wavelength sensing range of the respective tunable optical filter.

18. The multispectral sensing system of claim 17 , wherein:

the pixels comprises red, green, blue, and infrared pixels.