Color separation element and image sensor including the same

1. A color separation element in an image sensor comprising:

a spacer layer;

a color separation lens array comprising at least one nano-post provided on the spacer layer, the color separation lens array configured to control a phase distribution of incident light so that light having a same wavelength of the incident light is multi-focused on a plurality of target regions; and wherein the at least one nano-post is repeatedly arranged in a plurality of periodic regions; and

a plurality of periodic regions in which the color separation lens array is repeatedly arranged,

wherein each of the periodic regions comprises a plurality of pixels arranged two-dimensionally, and pixels of a same wavelength light, among the plurality of pixels, are arranged adjacent to each other in at least one of a horizontal direction and a vertical direction of the two-dimensional arrangement, and

wherein the plurality of target regions correspond to the pixels of the same wavelength light arranged adjacent to each other in at least one of the horizontal direction and the vertical direction of the two-dimensional arrangement.

2. The color separation element of claim 1 , wherein each of the plurality of periodic regions comprises a first group pixel region including a plurality of first pixels for focusing first wavelength light, respectively, a second group pixel region including a plurality of second pixels for focusing second wavelength light, respectively, a third group pixel region including a plurality of third pixels for focusing third wavelength light, respectively, and a fourth group pixel region including a plurality of fourth pixels for focusing first wavelength light, respectively,

wherein the first group pixel region and the fourth group pixel region are located in a diagonal direction, and the second group pixel region and the third group pixel region are located in a diagonal direction.

3. The color separation element of claim 2 , wherein the first wavelength light comprises green light, the second wavelength light comprises blue light, and the third wavelength light comprises red light.

4. The color separation element of claim 2 , wherein the plurality of first pixels in the first group pixel region are adjacently disposed, the plurality of second pixels in the second group pixel region are adjacently disposed, the plurality of third pixels in the third group pixel region are adjacently disposed, and the plurality of fourth pixels in the fourth group pixel region are adjacently disposed.

5. The color separation element of claim 2 , wherein the color separation element is configured so that the first wavelength light has a phase of 2Nπ(N is an integer greater than 0) at the center of each pixel in the first group pixel region, and the phase is gradually decreased toward a periphery of the periodic region.

6. The color separation element of claim 2 , wherein the color separation element is configured so that the second wavelength light has a phase of 2Mπ(M is an integer greater than 0) at the center of each pixel in the second group pixel region and the phase is gradually decreased toward a periphery of the periodic region.

7. The color separation element of claim 2 , wherein the color separation element is configured so that the third wavelength light has a phase of 2Lπ(L is an integer greater than 0) at the center of each pixel in the third group pixel region and the phase is gradually decreased toward a periphery of the periodic region.

8. The color separation element of claim 1 , wherein each of plurality of periodic regions comprises a first 2×2 group pixel region where first wavelength light is focused, a second 2×2 group pixel region where second wavelength light is focused, a third 2×2 group pixel region where third wavelength light is focused, and a fourth 2×2 group pixel region where the first wavelength light is focused, respectively,

wherein the first 2×2 group pixel region and the fourth 2×2 group pixel region are located in a diagonal direction, and the second 2×2 group pixel region and the third 2×2 group pixel region are located in a diagonal direction.

9. The color separation element of claim 1 , wherein each of the periodic regions comprises a first 3×3 group pixel region where first wavelength light is focused, a second 3×3 group pixel region where second wavelength light is focused, a third 3×3 pixel region where the third wavelength light is focused, and a fourth 3×3 group pixel region where the first wavelength light is focused, respectively,

wherein the first 3×3 group pixel region and the fourth 3×3 group pixel region are located in a diagonal direction, and the second 3×3 group pixel region and the third 3×3 group pixel region are located in a diagonal direction.

10. The color separation element of claim 1 , wherein each of the periodic region comprises a first 3×3 group pixel region where first wavelength light is focused, a second 3×3 group pixel region where second wavelength light and third wavelength light are focused, a third 3×3 group pixel region where second wavelength light and third wavelength light are focused, and a fourth 3×3 group pixel region where first wavelength light is focused.

11. The color separation element of claim 1 , wherein the color separation lens array is configured to diverge incident light by wavelength and to control the phase distribution so that light of the same wavelength is multi-focused.

12. An image sensor comprising:

an optical sensor including a plurality of photosensitive cells for sensing light;

a spacer layer provided on the optical sensor;

a color separation lens array comprising at least one nano-post provided on the spacer layer to control a phase distribution of incident light so that light having the same wavelength of the incident light is multi-focused on a plurality of target regions; and

a plurality of periodic regions in which the color separation lens array is repeatedly arranged,

wherein each of the periodic regions comprises a plurality of pixels arranged two-dimensionally, and pixels of a same wavelength light, among the plurality of pixels, are arranged adjacent to each other in at least one of a horizontal direction and a vertical direction of the two-dimensional arrangement, and

wherein the plurality of target regions correspond to the pixels of the same wavelength light arranged adjacent to each other in at least one of the horizontal direction and the vertical direction of the two-dimensional arrangement.

13. The image sensor of claim 12 , wherein each of the plurality of periodic regions comprises a first group pixel region including a plurality of first photosensitive cells for focusing first wavelength light, respectively, a second group pixel region including a plurality of second photosensitive cells for focusing second wavelength light, respectively, a third group pixel region including a plurality of third photosensitive cells for focusing third wavelength light, respectively, and a fourth group pixel region including a plurality of fourth photosensitive cells for focusing first wavelength light, respectively,

wherein the first group pixel region and the fourth group pixel region are located in a diagonal direction, and the second group pixel region and the third group pixel region are located in a diagonal direction.

14. The image sensor of claim 13 , wherein the first wavelength light comprises green light, the second wavelength light comprises blue light, and the third wavelength light comprises red light.

15. The image sensor of claim 13 , wherein the image sensor is configured so that the first wavelength light has a phase of 2Nπ(N is an integer greater than 0) at the center of each pixel in the first group pixel region, and the phase is gradually decreased toward a periphery of the periodic region.

16. The image sensor of claim 13 , wherein the image sensor is configured so that the second wavelength light has a phase of 2Mπ(M is an integer greater than 0) at the center of each pixel in the second group pixel region and the phase is gradually decreased toward a periphery of the periodic region.

17. The image sensor of claim 13 , wherein the image sensor is configured so that the third wavelength light has a phase of 2Lπ(L is an integer greater than 0) at the center of each pixel in the third group pixel region and the phase is gradually decreased toward a periphery of the periodic region.

18. The image sensor of claim 12 , wherein each of the plurality of periodic region comprises a first 2×2 group pixel region where first wavelength light is focused, a second 2×2 group pixel region where second wavelength light is focused, a third 2×2 group pixel region where third wavelength light is focused, and a fourth 2×2 group pixel region where the first wavelength light is focused, respectively,

wherein the first 2×2 group pixel region and the fourth 2×2 group pixel region are located in a diagonal direction, and the second 2×2 group pixel region and the third 2×2 group pixel region are located in a diagonal direction.

19. The image sensor of claim 12 , wherein each of the plurality of periodic regions comprises a first 3×3 group pixel region where first wavelength light is focused, a second 3×3 group pixel region where second wavelength light is focused, a third 3×3 pixel region where the third wavelength light is focused, and a fourth 3×3 group pixel region where first wavelength light is focused, respectively,

wherein the first 3×3 group pixel region and the fourth 3×3 group pixel region are located in a diagonal direction, and the second 3×3 group pixel region and the third 3×3 group pixel region are located in a diagonal direction.

20. The image sensor of claim 12 , wherein the color separation lens array is configured to control a phase distribution of incident light so that the incident light is diverged by wavelength and light of the same wavelength is multi-focused.