Nanostructured optical element, depth sensor, and electronic device

1. A depth recognition apparatus comprising:

a projector;

a first sensor, disposed in a first position with respect to the projector, and configured to receive light from an object;

a second sensor, disposed in a second position with respect to the projector, different from the first position, and configured to receive light from the object; and

a processor configured to analyze the light received by at least one of the first and second sensors and thereby calculate a depth position of the object,

wherein the projector comprises:

a light source comprising an array of a plurality of laser sources outputting light;

a meta-pattern layer comprising a two-dimensional array of a plurality of first nano-posts, wherein each of the plurality of first nano-posts has a dimension smaller than a wavelength of light output by the plurality of laser sources, and wherein the meta-pattern layer is configured to convert light incident thereon into structured light; and

a deflecting layer between the light source and the meta-pattern layer, the deflecting layer configured to direct light from the light source onto the meta-pattern layer,

wherein the processor is further configured to:

obtain first depth information about the object by analyzing the structured light emitted from the projector onto the object and the light received by the first sensor;

obtain second depth information about the object by analyzing the structured light emitted from the projector onto the object and the light received by the second sensor; and

calculate the depth position of the object based on the first depth information and the second depth information.

2. The depth recognition apparatus of claim 1 , wherein the processor is further configured to:

obtain first image data from light received by the first sensor;

obtain second image data from light received by the second sensor; and

calculate the depth position of the object based on the first image data and the second image data.

3. The depth recognition apparatus of claim 1 , wherein the deflecting layer comprises one of a convex lens and a Fresnel lens.

4. The depth recognition apparatus of claim 1 , wherein the deflecting layer comprises a two-dimensional array of a plurality of second nano-posts, wherein each of the plurality of second nano-posts has a dimension smaller than the wavelength of light output by the plurality of laser sources.

5. The depth recognition apparatus of claim 4 , further comprising:

a supporting layer between the meta-pattern layer and the deflecting layer,

wherein the meta-pattern layer is disposed on a first surface of the supporting layer, and the deflecting layer is disposed on a second surface of the supporting layer, opposite the first surface.

6. The depth recognition apparatus of claim 1 , wherein the meta-pattern layer further comprises a supporting layer supporting the plurality of first nano-posts, and the meta-pattern layer has a refractive index that is at least one greater than a refractive index of the supporting layer.

7. The depth recognition apparatus of claim 1 , wherein the array of the plurality of first nano-posts comprises one of a hexagonal lattice and a rectangular lattice.

8. The depth recognition apparatus of claim 1 , wherein a shape of at least a first one of the plurality of first nano-posts is different from a shape of at least a second one of the plurality of first nano-posts.

9. The depth recognition apparatus of claim 1 , wherein at least one of a width and a height of at least a first one of the plurality of first nano-posts is different from at least one of a width and a height of a second one of the plurality of first nano-posts.

10. The depth recognition apparatus of claim 1 , wherein each of the plurality of first nano-posts has a multi-layered structure.

11. The depth recognition apparatus of claim 1 , wherein the plurality of first nano-posts are configured such that the structured light output from the meta-pattern layer does not overlap in a spatial frequency domain.

12. The depth recognition apparatus of claim 1 , wherein the plurality of first nano-posts are configured such that the structured light output from the meta-pattern layer overlaps in a spatial frequency domain.

13. A depth recognition apparatus comprising:

a projector;

a first sensor, disposed in a first position with respect to the projector, and configured to receive light from an object;

a second sensor, disposed in a second position with respect to the projector, different from the first position, and configured to receive light from the object;

an ambient light sensor configured to sense illuminance in an area surrounding the object; and

a processor configured to analyze the light received by at least one of the first and second sensors and thereby calculate a depth position of the object,

wherein the projector comprises:

a light source comprising an array of a plurality of laser sources outputting light;

a meta-pattern layer comprising a two-dimensional array of a plurality of first nano-posts, wherein each of the plurality of first nano-posts has a dimension smaller than a wavelength of light output by the plurality of laser sources, and wherein the meta-pattern layer is configured to convert light incident thereon into structured light; and

a deflecting layer between the light source and the meta-pattern layer, the deflecting layer configured to direct light from the light source onto the meta-pattern layer, and

wherein the processor is further configured to turn off the projector based on a signal sensed by the ambient light sensor being equal to or greater than a given value.

14. The depth recognition apparatus of claim 13 , wherein when the projector is in an off-state, the processor is further configured to:

obtain first image data about the object from a signal output from the first sensor based on ambient light reflected from the object and received by the first sensor;

obtain second image data about the object from a signal output from the second sensor based on ambient light reflected from the object and received by the second sensor; and

calculate the depth position of the object based on the first image data and the second image data.

15. A depth recognition apparatus comprising:

a projector;

a first sensor, disposed in a first position with respect to the projector, and configured to receive light from an object;

a second sensor, disposed in a second position with respect to the projector, different from the first position, and configured to receive light from the object; and

a processor configured to analyze the light received by at least one of the first and second sensors and thereby calculate a depth position of the object,

wherein the projector comprises:

a light source comprising an array of a plurality of laser sources outputting light;

a meta-pattern layer comprising a two-dimensional array of a plurality of first nano-posts, wherein each of the plurality of first nano-posts has a dimension smaller than a wavelength of light output by the plurality of laser sources, and wherein the meta-pattern layer is configured to convert light incident thereon into structured light; and

a deflecting layer between the light source and the meta-pattern layer, the deflecting layer configured to direct light from the light source onto the meta-pattern layer, and

wherein the processor is further configured to:

when the projector is on, obtain primary-first image data and secondary-first image data based on light received by the first sensor and the second sensor, respectively; and

when the projector is off, obtain primary-second image data and secondary-second image data from light received by the first sensor and the second sensor, respectively.

16. The depth recognition apparatus of claim 15 , wherein the processor is further configured to:

calculate first depth information about the object based on the primary-first image data and the secondary-first image data;

calculate second depth information about the object based on the primary-second image data and the secondary-second image data; and

calculate the depth position of the object based on the first depth information and the second depth information.

17. The depth recognition apparatus of claim 15 , wherein the processor is further configured to:

calculate first difference image data based on a difference between the primary-first image data and the primary-second image data;

calculate second difference image data based on a difference between the secondary-first image data and the secondary-second image data; and

calculate the depth position of the object based on the first difference image data and the second difference image data.

18. A depth recognition apparatus comprising:

a projector;

a first sensor, disposed in a first position with respect to the projector, and configured to receive light from an object;

a second sensor, disposed in a second position with respect to the projector, different from the first position, and configured to receive light from the object; and

a processor configured to analyze the light received by at least one of the first and second sensors and thereby calculate a depth position of the object,

wherein the projector comprises:

a light source comprising an array of a plurality of laser sources outputting light;

a meta-pattern layer comprising a two-dimensional array of a plurality of first nano-posts, wherein each of the plurality of first nano-posts has a dimension smaller than a wavelength of light output by the plurality of laser sources, and wherein the meta-pattern layer is configured to convert light incident thereon into structured light; and

a deflecting layer between the light source and the meta-pattern layer, the deflecting layer configured to direct light from the light source onto the meta-pattern layer,

wherein at least one of the first sensor and the second sensor comprises:

a switchable filter configured to be switched between an infrared-cut mode, in which infrared light is blocked, and an infrared transmission mode, in which infrared light is transmitted therethrough; and

an image sensor configured to sense light transmitted through the switchable filter.

19. The depth recognition apparatus of claim 18 , wherein the processor is further configured to control the switchable filter to block infrared light in a normal photographic mode and to transmit infrared light in a depth recognition mode.