Method and electronic device for detecting wavelength spectrum of incident light

1. An electronic device, comprising:

an image sensor including a pixel array, wherein the pixel array includes a unit pixel including:

a micro lens configured to focus incident light, and

two or more photodetectors configured to output an electrical signal in response to the incident light; and

a processor configured to detect a wavelength spectrum of the incident light based on output values from the two or more photodetectors,

wherein when the unit pixel includes two photodetectors, a physical central point of the unit pixel and a central point of an optical spot formed on the two photodetectors by the incident light passing through the micro lens are spaced apart from each other by a specified distance.

2. The electronic device of claim 1 , wherein the processor is further configured to:

compute at least one parameter by using the output values from the two or more photodetectors, and

detect the wavelength spectrum of the incident light based on the at least one parameter.

3. The electronic device of claim 2 , further comprising a memory configured to store data associated with a correlation between the at least one parameter and the wavelength spectrum,

wherein the processor is further configured to detect the wavelength spectrum of the incident light based on the data associated with the correlation.

4. The electronic device of claim 1 , wherein the processor is further configured to determine a type of a light source producing the incident light by using the detected wavelength spectrum.

5. The electronic device of claim 4 , wherein the processor is further configured to apply white balance correction corresponding to the determined type of the light source to at least part of an image.

6. The electronic device of claim 1 , wherein the unit pixel further includes a color filter disposed below the micro lens to pass a specified wavelength range.

7. The electronic device of claim 1 , wherein an output difference between the output values from the two photodetectors occurs by a gap between the physical center point and the central point of the optical spot.

8. The electronic device of claim 1 , wherein the optical spot formed on the two photodetectors by the incident light through the micro lens is biased toward an outside of the image sensor with respect to a center point of the micro lens.

9. The electronic device of claim 1 , wherein the pixel array includes a first group of unit pixels, a second group of unit pixels, and a third group of unit pixels,

wherein each of the unit pixels in the first group includes a first photodetector, a second photodetector, and a first color filter passing light having a first wavelength range,

wherein each of the unit pixels in the second group includes a first photodetector, a second photodetector, and a second color filter passing light having a second wavelength range,

wherein each of the unit pixels in the third group includes a first photodetector, a second photodetector, and a third color filter passing light having a third wavelength range, and

wherein the processor is further configured to detect the wavelength spectrum of the incident light by using a value that is obtained by dividing a sum of a first output value from the first photodetector and a second output value from the second photodetector by the second output value, for each unit pixel of each group.

10. The electronic device of claim 9 , wherein the processor is further configured to detect the wavelength spectrum of the incident light by further using a ratio of sums of output values in the first group of unit pixels, the second group of unit pixels, and the third group of unit pixels.

11. The electronic device of claim 9 , wherein the first wavelength range, the second wavelength range, and the third wavelength range include a wavelength range corresponding to red, a wavelength range corresponding to green, and a wavelength range corresponding to blue, respectively.

12. The electronic device of claim 1 , wherein the unit pixel includes three or more photodetectors, and

wherein a physical center point of the unit pixel and a center point of an optical spot formed on the three or more photodetectors by the incident light are set to coincide with each other.

13. The electronic device of claim 1 , wherein each of the two or more photodetectors includes a photo diode.

14. A wavelength detecting method of an electronic device including a plurality of unit pixels, the method comprising:

obtaining two or more electrical signals from a unit pixel in response to incident light; and

detecting a wavelength spectrum of the incident light based on output values of the two or more electrical signals,

wherein when the unit pixel includes two photodetectors, a physical central point of the unit pixel and a central point of an optical spot formed on the two photodetectors by the incident light passing through a micro lens are spaced apart from each other by a specified distance.

15. The method of claim 14 , further comprising calculating a specified parameter by using the output values of the two or more electrical signals,

wherein the wavelength spectrum of the incident light is detected based on the specified parameter.

16. The method of claim 14 , further comprising determining a type of a light source producing the incident light based on the detected wavelength spectrum.

17. The method of claim 16 , further comprising applying white balance correction corresponding to the determined type of the light source to at least part of an image.

18. The method of claim 15 , wherein the plurality of unit pixels include a first group of unit pixels, a second group of unit pixels, and a third group of unit pixels,

wherein each of the unit pixels in the first group includes a first photodetector, a second photodetector, and a first color filter passing light having a first wavelength range,

wherein each of the unit pixels in the second group includes a first photodetector, a second photodetector, and a second color filter passing light having a second wavelength range,

wherein each of the unit pixels in the third group includes a first photodetector, a second photodetector, and a third color filter passing light having a third wavelength range, and

wherein the calculating of the specified parameter comprises dividing a sum of a first output value from the first photodetector and a second output value from the second photodetector by the second output value, for each unit pixel of each group.

19. The method of claim 18 , wherein calculating the specified parameter further comprises obtaining a ratio of sums of output values in the first group of unit pixels, the second group of unit pixels, and the third group of unit pixels.