Rolling camera system

1. A 3D imaging system, comprising:

first and second rolling shutter photosurfaces comprising pixels;

a first shutter operable to gate on and off the first rolling shutter photosurface;

a light source controllable to transmit a train of infrared light pulses to illuminate a scene;

a controller that controls the first shutter to gate the first rolling shutter photosurface on and off responsive to transmission times of the light pulses and opens and closes bands of pixels in the first and second rolling shutter photosurfaces to register reflected light, the reflected light is reflected from the light pulses by the scene; and

a processor that determines distances to the scene responsive to amounts of light registered by pixels in the first and second rolling shutter photosurfaces, wherein the first and second rolling shutter photosurfaces comprise respective arrays of pixels, the first rolling shutter registers substantially only infrared light from the scene, and the second rolling shutter photosurface registers infrared and RGB light from the scene.

2. The 3D imaging system according to claim 1 , wherein:

the controller opens and closes homologous bands of pixels in the first and second rolling shutter photosurfaces to register reflected light that reaches the 3D imaging system from same transmitted light pulses.

3. The 3D imaging system according to claim 1 , wherein:

the controller controls the first shutter to gate on and off the first rolling shutter photosurface, and turns on and off bands of pixels in the first rolling shutter photosurface to register light from the scene during periods of time for which reflected light from the light pulses does not reach the 3D imaging system.

4. The 3D imaging system according to claim 3 , wherein:

the processor determines a distance to a region of the scene responsive to an amount of the reflected light which is from the region and registered by the first rolling shutter photosurface minus an amount of light registered by the first rolling shutter photosurface during a period of time for which reflected light from the light pulses does not reach the 3D imaging system.

5. The 3D imaging system according to claim 3 , wherein:

the controller turns on and off bands of pixels in the second rolling shutter photosurfaces to register light from the scene during periods of time for which reflected light from the light pulses does not reach the 3D imaging system.

6. The 3D imaging system according to claim 5 , wherein:

the controller turns on and off homologous bands of pixels in the first and second rolling shutter photosurfaces to register light from the scene during same periods of time for which reflected light from the light pulses does not reach the 3D imaging system.

7. The 3D imaging system according to claim 5 , wherein:

the processor provides an image of the scene responsive substantially only to an amount of light from the scene registered by the second rolling shutter photosurface during periods of time for which reflected light from the light pulses does not reach the 3D imaging system minus an amount of light registered by the first rolling shutter photosurface during periods of time for which reflected light from the light pulses does not reach the 3D imaging system.

8. The 3D imaging system according to claim 1 , wherein:

the controller turns on and off bands of pixels in the second rolling shutter photosurface to register light from the scene during periods of time for which reflected light from the light pulses does not reach the 3D imaging system.

9. The 3D imaging system according to claim 8 , wherein:

the processor provides an image of the scene responsive substantially only to an amount of light from the scene registered by the second rolling shutter photosurface during periods of time for which light from the light pulses does not reach the 3D imaging system.

10. The 3D imaging system according to claim 8 , wherein:

the processor determines a distance to a region of the scene responsive to an amount of the reflected light which is from the region and registered by the second rolling shutter photosurface minus an amount of light registered by the second rolling shutter photosurface during periods of time for which light from the light pulses does not reach the 3D imaging system.

11. The 3D imaging system according to claim 1 , further comprising:

a second shutter operable to gate on and off the second rolling shutter photosurface.

12. The 3D imaging system of claim 1 , further comprising:

optics which direct half of the reflected light to each of the first and second rolling shutter photosurfaces.

13. The 3D imaging system according to claim 1 , further comprising:

a second shutter operable to gate on and off the second rolling shutter photosurface; wherein:

the controller controls the first shutter to gate on and off the first rolling shutter photosurface responsive to times at which the light pulses in the train of light pulses are transmitted to register the reflected light; and

the controller controls the second shutter to gate on the second rolling shutter photosurface for a period which extends over multiple light pulses of the train of light pulses.

14. The 3D imaging system according to claim 1 , further comprising:

an infrared filter in front of the first rolling shutter photosurface but not in front of the second rolling shutter photosurface.

15. A method of 3D imaging a scene, the method comprising:

transmitting a train of infrared light pulses to illuminate the scene;

gating a first rolling shutter photosurface on and off responsive to times at which light pulses in the train of light pulses are transmitted to register reflected light, the reflected light is reflected from the light pulses by the scene, wherein the first rolling shutter photosurface comprises a respective array of pixels and registers substantially only infrared light from the scene;

imaging the scene with a second rolling shutter photosurface comprising a respective array of pixels, wherein the second rolling shutter photosurface registers infrared and RGB light from the scene; and

using light registered by the first rolling shutter photosurface and the second rolling shutter photosurface to provide a depth map of the scene and an image of the scene.

16. The method according to claim 15 , wherein:

the first and second rolling shutter photosurfaces are homologous such that pixels corresponding to a same relative position on each of the first and second rolling shutter photosurfaces receive the reflected light from substantially a same region of the scene.

17. The method according to claim 15 , further comprising:

gating the second rolling shutter photosurface on over for a period which extends over multiple light pulses of the train of light pulses.

18. The method according to claim 15 , further comprising:

opening and closing homologous bands of pixels in the first and second rolling shutter photosurfaces to register the reflected light.

19. The method according to claim 18 , further comprising:

turning on and off homologous bands of pixels in the first and second rolling shutter photosurfaces to register light from the scene during same periods of time for which light from the light pulses does not reach the 3D imaging system.

20. The method according to claim 15 , further comprising:

directing half of the reflected light to each of the first and second rolling shutter photosurfaces.