Lens array imaging with cross-talk inhibiting optical stop structure
View Patent ↗An apparatus includes an optical sensor, a lens system, and an optical stop system. The optical sensor includes photocells each of which has a respective photocell active area in a capture plane. The lens system includes lenses each of which is operable to focus light from a respective subfield of a scene into a corresponding focused beam. The optical stop system includes aperture systems each of which confines a corresponding one of the focused beams to a respective illumination area in the capture plane. In a method, light from respective subfields of a scene is focused into corresponding focused beams. Corresponding ones of the focused beams are confined to respective non-overlapping illumination areas in the capture plane. Optical data is generated from light of the focused beams illuminating the illumination areas. Motion measures indicative of movement in relation to the scene are produced from the optical data.
1. An apparatus, comprising:
an optical sensor comprising photocells each having a respective photocell active area in a capture plane;
a lens system comprising lenses each operable to focus light from a respective subfield of a scene into a corresponding focused beam; and
an optical stop system comprising aperture systems each confining a corresponding one of the focused beams to a respective illumination area in the capture plane,
wherein each of the aperture systems is defined by a cavity having an input aperture and an output aperture, wherein the size of the output aperture is greater than the size of the input aperture, wherein the shape of each of the output aperture and the input aperture is a polygon, and wherein the output aperture is configured relative to the configuration of the input aperture and in such a way that causes the cavity defined thereby to confine the illumination area of its respective aperture system in such a way that the illumination area does not overlap with the illumination area of adjacent aperture systems.
2. The apparatus of claim 1 , wherein each of the lenses is aligned with a respective one of aperture systems along a respective optical axis.
3. The apparatus of claim 2 , wherein each of the illumination areas is centered with respect to a respective one of the optical axes.
4. The apparatus of claim 1 , wherein the lens system comprises a front side and a back side, the front side comprises an array of curved surfaces corresponding to respective ones of the lenses, and the back side comprises a planar surface adjacent the optical stop system.
5. The apparatus of claim 1 , wherein the illumination areas respectively encompass mutually exclusive sets of one or more of the photocell active areas.
6. The apparatus of claim 1 , wherein the optical stop system confines the focused beams to respective non-overlapping illumination areas in the capture plane.
7. The apparatus of claim 1 , wherein the optical stop system is incorporated in an optical stop structure between the lens system and the optical sensor.
8. The apparatus of claim 7 , wherein the optical stop structure comprises a substrate that is opaque to light within a specified wavelength range, and the substrate comprises cavities each defining a respective one of the aperture systems.
9. The apparatus of claim 8 , wherein each of the cavities comprises an input aperture and an output aperture, the input aperture passes at least a portion of a corresponding one of the focused beams, and the output aperture defines boundaries in the capture plane between the respective illumination area and a respective shadow zone free of any light from the passed portion of the corresponding focused beam.
10. The apparatus of claim 8 , wherein each of the cavities has frustopyramidal sidewalls.
11. The apparatus of claim 1 , wherein each of the aperture systems includes an input aperture on an object side of the lens system and an output aperture between the lens system and the optical sensor.
12. The apparatus of claim 1 , wherein each of the aperture systems comprises an input aperture and an output aperture, the input aperture passes at least a portion of a corresponding one of the focused beams, and the output aperture blocks light in the passed portion of the corresponding focused beam directed to areas of the capture plane outside of the respective illumination area.
13. The apparatus of claim 12 , wherein each of the input apertures is rectangular and each of the output apertures is rectangular.
14. The apparatus of claim 1 wherein each of the lenses has a respective front focal plane and a respective back focal plane that coincides with the capture plane, wherein the distances between each front focal plane and the capture plane is less than 5 millimeters.
15. The apparatus of claim 1 , wherein the optical sensor, the lens system, and the optical stop structure are integrated into a unitary structure.
16. The apparatus of claim 1 , wherein the optical sensor is operable to generate optical data from light focused by the lenses onto the illumination areas, and further comprising a processing system operable to produce motion measures indicative of movement in relation to the scene from the optical data.
17. The apparatus of claim 16 , wherein the optical sensor is operable to capture successive images composed of images the subfields focused onto the photocell active areas in the illumination areas, and the processing system produces motion measures from comparisons of ones of the captured images.
18. The apparatus of claim 1 , wherein the lens system and the optical stop system form light from the scene into a parallel array of the focused beams, each of the lenses is aligned spatially with a corresponding one of the aperture systems to define a respective image-forming light channel, and light from the subfields of the scene passes through different respective ones of the image-forming light channels to form respective images of the respective subfields in respective ones of the illumination areas in the capture plane.
19. The apparatus of claim 18 , wherein each of the aperture systems comprises a respective aperture stop that is paired with a respective spatially-aligned field stop, and each of the pairs of the aperture stops and the field stops determines a respective cone angle of a respective light ray bundle of light from a respective one of the subfields in the respective one of the image-forming light channels.
20. The apparatus of claim 1 , wherein the focused beams have different respective parallel optical axes.
21. The apparatus of claim 1 , wherein the lenses are arranged in a planar array.
22. A system, comprising:
means for focusing light from respective subfields of a scene into corresponding focused beams;
means for confining corresponding ones of the focused beams to respective non-overlapping illumination areas in the capture plane,
wherein the confining means includes aperture systems each defined by a cavity having an input aperture and an output aperture,
wherein the size of the output aperture is greater than the size of the input aperture,
wherein the shape of each of the output aperture and the input aperture is a polygon, and
wherein the output aperture is configured relative to the configuration of the input aperture and in such a way that causes the cavity defined thereby to confine the illumination area of its respective aperture system in such a way that the illumination area does not overlap with the illumination area of adjacent aperture systems;
means for generating optical data from light of the focused beams illuminating the illumination areas; and
means for producing motion measures indicative of movement in relation to the scene from the optical data.
23. A method, comprising:
focusing light from respective subfields of a scene into corresponding focused beams;
confining corresponding ones of the focused beams to respective non-overlapping illumination areas in the capture plane by configuring an output aperture and an input aperture of a cavity defined thereby in an aperture system corresponding to the focused beams in such a way that the size of the output aperture is greater than the size of the input aperture and the shape of each of the output aperture and the input aperture is a polygon;
generating optical data from light of the focused beams illuminating the illumination areas; and
producing motion measures indicative of movement in relation to the scene from the optical data.
24. The method of claim 23 , wherein the confining comprises passing at least a portion of a corresponding one of the focused beams, and blocking light in the passed portion of the corresponding focused beam directed to areas of the capture plane outside of the respective illumination area.
25. The method of claim 23 , further comprising producing motion measures indicative of movement in relation to the scene from the optical data.
26. The method of claim 23 , wherein the generating comprises capturing successive images composed of images of the subfields focused onto the illumination areas, and the producing comprises producing motion measures from comparisons of ones of the captured images.
27. An apparatus, comprising:
an optical sensor comprising photocells each having a respective photocell active area in a capture plane;
a lens system comprising lenses each operable to focus light from a different respective subfield of a scene into a corresponding one of multiple focused beams having different respective parallel optical axes; and
an optical stop system comprising aperture systems each confining a corresponding one of the focused beams to a different respective illumination area in the capture plane, wherein each of the focused beams forms a respective image in a respective one of the illumination areas,
wherein each of the aperture systems is defined by a cavity having an input aperture and an output aperture, wherein the size of the output aperture is greater than the size of the input aperture, wherein the shape of each of the output aperture and the input aperture is a polygon, and wherein the output aperture is configured relative to the configuration of the input aperture and in such a way that causes the cavity defined thereby to confine the illumination area of its respective aperture system in such a way that the illumination area does not overlap with the illumination area of adjacent aperture systems.
28. The apparatus of claim 27 , wherein each of the aperture systems comprises a respective aperture stop that is paired with a respective spatially-aligned field stop, and each of the pairs of the aperture stops and the field stops determines a respective cone angle of a respective light ray bundle of light from a respective one of the subfields in the respective one of the focused beams.