Thin camera having sub-pixel resolution
View Patent ↗A thin camera having sub-pixel resolution includes an array of micro-cameras. Each micro-camera includes a lens, a plurality of sensors of size p, and a plurality of macro-pixels of size d having a feature of size q. The feature size q smaller than p and provides a resolution for the micro-camera greater than p. The smallest feature in the micro-cameras determines the resolution of the thin camera. Each macro-pixel may have any array of m features of size q, where q=d/m. Additional micro-cameras may be included to increase power.
1. An imaging system comprising:
an array of lenses;
a plurality of sensors for each lens, each sensor having a single detection element of size P x P y , with the center-to-center spacing of the detection elements being d x in the x-direction and d y in the y-direction, the plurality of sensors being adjacent to an image plane of a corresponding lens; and
a plurality of macro-pixels of size d x d y , each macro-pixel corresponding to a sensor and being between the corresponding lens and the sensor, each macro-pixel having m x m y micro-pixels, each micro-pixel being of size d x /m x *d y /m y and having one of a high and a low transmittance function,
wherein light transmitted through each lens and directed towards a sensor will impinge on the sensor after multiplication by the transmittance of the macro-pixel, and
wherein the imaging system has a resolution in the image plane of greater than 1/p x in the x-direction or 1/p y in the y-direction.
2. The imaging system as recited in claim 1 , wherein a ratio of a size of each macro-pixel to a size of each micro-pixel is proportional to a number of lenses in the array of lenses.
3. The imaging system as recited in claim 1 , wherein the size d x /m x *d y /m y is on an order of a desired resolution of the imaging system.
4. The imaging system as recited in claim 1 , wherein all m micro-pixels for a corresponding macro-pixel have high transmittance.
5. The imaging system as recited in claim 1 , wherein only one micro-pixel for a corresponding macro-pixel has high transmittance.
6. The imaging system as recited in claim 1 , wherein a number of lenses in the x-direction is different from the number of lenses in the y-direction.
7. The imaging system as recited in claim 1 , wherein the high transmittance is one and the low transmittance is zero.
8. The imaging system as recited in claim 1 , wherein the high transmittance is greater than 0.5 and the low transmittance is less than 0.5.
9. The imaging system as recited in claim 1 , wherein a majority of the macro-pixels have at least 20% high transmittance micro-pixels.
10. The imaging system as recited in claim 1 , wherein the lens is formed on one side of a substrate and the plurality of macro-pixels is formed on an opposite side of the substrate.
11. The imaging system as recited in claim 1 , wherein the plurality of macro-pixels is formed on the lens.
12. The imaging system as recited in claim 1 , wherein at least part of a path between the lens and the array of macro-pixels has a refractive index greater than one.
13. The imaging system as recited in claim 12 , wherein a majority of the path has a refractive index greater than one.
14. The imaging system as recited in claim 1 , wherein one filtering element allows all the light incident thereon to impinge on the macro-pixel.
15. The imaging system as recited in claim 1 , further comprising different color filters in paths of corresponding macro-pixels.
16. The imaging system as recited in claim 1 , wherein the lens includes a substrate having parallel surfaces, an optical element being formed on at least one of the parallel surfaces.
17. The imaging system as recited in claim 1 , wherein the lens includes at least two substrates having parallel surfaces, at least two optical elements, each optical element being formed on a different surface of the at least two of the parallel surfaces.
18. The imaging system as recited in claim 17 , wherein one optical element of the least two optical elements is a diffractive optical element.
19. The imaging system as recited in claim 17 , wherein the diffractive optical element corrects for aberration of the lens.
20. The imaging system as recited in claim 17 , wherein the at least two substrates for an array of lenses are bonded together.
21. The imaging system as recited in claim 17 , further comprising a spacer between the at least two substrates.
22. The imaging system as recited in claim 1 , wherein d x d y =p x p y .
23. The imaging system as recited in claim 1 , wherein each lens in array of lenses is a polygonal lens and corresponding macro-pixels and sensors fill in similarly sized area to that of the polygonal lens.
24. The imaging system as recited in claim 1 , further comprising a processor receiving outputs from the plurality of sensors and combining outputs from corresponding sensors for different lenses.