Method and apparatus for providing adaptive illumination

• US 20040114921A1
• Filed: 10/02/2003
• Published: 06/17/2004
• Est. Priority Date: 02/16/1999
• Status: Active Grant

• Current Assignee: Microsoft International Holdings BV (Microsoft Corporation)
• Original Assignee: 3DV Systems Ltd. (Microsoft Corporation)
• Inventors: Yahav, Giora, Braun, Ori J.
• Granted Patent: US 6,993,255 B2
• Time in Patent Office: Days
• US Class Current: 396/661
• CPC Class Codes: B60Q 2400/50 Projected symbol or information, e.g. onto the road or car body
• CPC Class Codes: B60Q 9/008 for anti-collision purposes
• CPC Class Codes: F21S 41/141 Light emitting diodes [LED]
• CPC Class Codes: F21S 41/147 the main emission direction of the LED being angled to the optical axis of the illuminating device
• CPC Class Codes: F21S 41/663 by switching light sources by switching incandescent light sources F21S41/162
• CPC Class Codes: G01C 11/025 by scanning the object
• CPC Class Codes: G01S 17/08 for measuring distance only indirect measurement G01S17/46; active triangulation systems G01S17/48
• CPC Class Codes: G01S 17/18 wherein range gates are used
• CPC Class Codes: G01S 17/88 Lidar systems specially adapted for specific applications
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/4812 transmitted and received beams following a coaxial path
• CPC Class Codes: G01S 7/51 Display arrangements
• CPC Class Codes: G02B 7/32 using active means, e.g. light emitter including both an active and a passive focus detecting device G02B7/285; using ultrasound G02B7/40
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means

Abstract

An illumination system (20, 72, 110, 142) for illuminating a scene comprising: an illuminator (24, 74, 116) having a plurality of substantially contiguous independently controllable light (26, 76) providing regions each of which provides light that illuminates a different region of the scene; optics (30) that directs light from the illuminator to the scene; a range finder (22, 64, 112) that determines distances to regions of the scene; and a controller (28, 29, 118) that controls the plurality of light providing regions to provide light for illuminating the scene responsive to distances determined by the range finder (22, 64, 112).

Claims

1. An illumination system for illuminating a scene comprising:

an illuminator having a plurality of substantially contiguous independently controllable light providing regions each of which provides light that illuminates a different region of the scene;

optics that directs light from the illuminator to the scene;

a range finder that determines distances to regions of the scene; and

a controller that controls the plurality of light providing regions to provide light for illuminating the scene responsive to distances determined by the range finder.

2. An illumination system according to claim 1 wherein the range finder comprises a 3D range-camera, the 3D range-camera comprising a gated photosurface having pixels and collecting optics that collects light from the scene and images the collected light on the photosurface.

3. An illumination system according to claim 2 wherein there is a one to one correspondence between light providing regions and pixels of the photosurface and light from a region of the scene illuminated with light from substantially only one light providing region is imaged substantially only on the pixel corresponding to the light providing region.

4. An illumination system according to claim 2 wherein there is a one to many correspondence between light providing regions and pixels so that each light providing region corresponds to a group of contiguous pixels and wherein light from a region of the scene illuminated by a light providing region is imaged substantially only on the light providing region'"'"'s corresponding group of pixels.

5. An illumination system according to claim 2 wherein there is a many to one correspondence between light providing regions and pixels so that each pixel corresponds to a group of contiguous light providing regions and wherein light from a region of the scene illuminated by light from a group of light providing regions is imaged substantially only on the group'"'"'s corresponding pixel.

6. An illumination system according to any of claims 2-5 wherein the collecting optics of the 3D range-camera is the optics that directs light to the scene.

7. An illumination system according to claim 6 wherein the photosurface is boresighted with the optics that directs light to the scenes so that a virtual image of the photosurface is substantially coincident with the illuminator.

8. An illumination system according to any of the preceding claims and comprising a shutter controllable to shutter light from the illuminator.

9. An illuminator according to claim 8 wherein the controller controls the shutter to shutter light from the illuminator so as to provide a train of light pulses that illuminates the scene.

10. An illumination system according to any of claims 2-7 wherein the controller turns on and turns off light providing regions of the plurality of light providing regions to provide a train of light pulses that illuminates the scene.

11. An illumination system according to claim 9 or claim 10 wherein the illuminator provides IR light and the train of light pulses comprises IR light pulses.

12. An illumination system according to any of claims 9-11 wherein the controller gates the photosurface on for at least one gate period at a time following a time at which each light pulse in the light pulse train is provided.

13. An illumination system according to claim 12 wherein the controller determines a distance to a region of the scene using an amount of light incident on a pixel of the photosurface that images the region during the at least one gate following each light pulse in the light pulse train.

14. An illumination system according to any of the preceding claims wherein the controller comprises a pattern recognition application which the controller uses to identify features and/or objects in images of the scene formed on the photosurface.

15. An illumination system according to claim 14 wherein the controller controls the light providing regions to provide light that illuminates the scene responsive to one or both of features and objects that it identifies in the image.

16. An illumination system according to claim 14 or claim 15 wherein the controller controls the 3D range-camera to acquire a first image of the scene at a first time and a second image of the scene at a second time and identifies a feature of the scene that has a location in the second image different from its location in the first image.

17. An illumination system according to claim 16 wherein the controller uses the difference in location of the feature, a difference between the first and second times, and distance of the feature from the illumination system to determine a transverse component of velocity of the feature in a direction substantially perpendicular to a direction along which the illumination system illuminates the feature.

18. An illumination system according to claim 17 wherein the controller controls the light providing regions to provide light that illuminates the scene responsive to the transverse component of velocity.

19. An illumination system according to any of the preceding claims wherein the controller controls the range finder to determine distances to a region of the scene at a first time and a second time and uses a difference in the distances and a difference between the first and second times to determine a radial component of velocity of the region along a direction substantially parallel to a direction along which the illumination system illuminates the region.

20. An illumination system according to claim 19 wherein the controller controls the light providing regions to provide light that illuminates the scene responsive to the radial component of velocity.

21. An illumination system according to any of the preceding claims wherein the controller controls the light providing regions to illuminate only regions of the scene that are located within a desired range of distances from the illumination system.

22. An illumination system according to any of the preceding claims wherein the controller controls intensity of light provided by light providing regions responsive to distances determined by the range finder.

23. An illumination system according to any of the preceding claims wherein the controller controls the light providing regions so that relative intensity of light provided by the illuminator that illuminates two different regions of the scene is substantially proportional to a ratio of the squares of their respective distances from the illumination system.

24. An illumination system according to any of the preceding claims wherein the optics that directs light to the scene focuses light from the illuminator to a plane whose distance relative to the illumination system is adjustable.

25. An illumination system according to claim 24 wherein the controller controls distance of the plane from the illumination system responsive to distance measurements to region of the scene.

26. An illumination system according to any of claims 1-23 wherein the optics that directs light to the scene focuses light from the illuminator to a plane whose distance relative to the illumination system is fixed.

27. An illumination system according to claim 26 wherein the position of the plane is located at infinity.

28. An illumination system according to any of claim 26 wherein the position of the plane is located at a distance from the illumination system that is an average of distances to scenes that the illumination system is intended to illuminate.

29. An illumination system according to any of the preceding claims wherein each light providing region provides white light.

30. An illumination system according to any of the preceding claims wherein each light providing region is controllable to provide R, G and B light in controllable amounts.

31. An illumination system according to any of the preceding claims wherein each light providing region provides IR light.

32. An illumination system according to any of claims 1-29 wherein the illuminator provides R, G, B and IR light and each light providing region provides one of R, G, B or IR light.

33. An illumination system according to claim 32 wherein the light providing regions are grouped in groups of four and wherein each one of the light providing region in a group provides a different one of R, G, B and IR light.

34. An illumination system according to any of claims 30, 32 or 33 wherein the controller controls intensity of R, G or B light provided by each light providing region so as to control hue, saturation or intensity of light illuminating a region of the scene which is illuminated by light from the light providing region independently of hue saturation and intensity of light illuminating other regions of the scene.

35. An illumination system according to claim 34 wherein the photosurface is color sensitive and the controller processes an image of the scene to determine color components of the scene.

36. An illumination system according to claim 35 wherein the controller controls intensity of R, G or B light provided by each light providing region so as to control hue, saturation or intensity of light illuminating the scene responsive to the determined color components.

37. An illumination system according to any of the preceding claims wherein the controller controls the 3D range-camera to repeatedly acquire an image of the scene and determine distances to regions of the scene at a frequency equal to or greater than 25 Hz.

38. An illumination system according claim 37 wherein following the acquisition of each image, the controller adjusts light provided by the light providing regions to match changes in the positions of one or both of features and objects in the scene relative to their positions in an immediately preceding image of the scene.

39. An illumination system according to claim 38 wherein a time lapse between acquisition of the image and a time at which the illuminator provides light adjusted responsive to the image is sufficiently short so that during the time lapse the positions of features and/or objects of the scene do not change sufficiently to generate a substantial mismatch between the illumination and the scene.

40. An illumination system according to claim 39 wherein the time lapse is less than about 50 milliseconds.

41. An illumination system according to claim 39 wherein the time lapse is less than about 25 milliseconds.

42. An illumination system according to any of the preceding claims wherein the controller is programmable to control the light providing regions to provide desired illumination effects.

43. An automotive light for use in a vehicle for illuminating a roadway scene comprising a portion of a road on which the vehicle is located and neighboring regions thereof, the automotive light comprising an illumination system according to any of claims 1-18.

44. An automotive light according to claim 43 wherein the controller controls the illumination system to determine distances to objects in the roadway scene at different times and uses a change in distance of an object as a function of time to determine if the vehicle and object are closing at a dangerous speed.

45. An automotive light according to claim 44 wherein if the controller determines that the vehicle and object are closing at a dangerous speed the controller controls the illumination system to generate an optical cue that alerts the driver to the danger.

46. An automotive light according to claim 45 wherein the optical cue comprises a spatial light pattern that the illumination system projects on the object.

47. An automotive light according to claim 45 wherein the optical cue comprises a spatial light pattern that the illumination system projects on the road.

48. An automotive light according to any of claims 45-47 wherein the light providing regions are controllable to provide different color light and wherein the optical cue is formed with colored light.

49. An automotive light according to any of claims 45-48 wherein the optical cue is time dependent.

50. An automotive light according to any of claims 43-49 wherein the controller processes images of the roadway scene provided by the photosurface to identify road signs in the roadway scene.

51. An automotive light according to claim 50 wherein when a roadway sign is identified, the controller controls the light providing regions to direct a beam of light that illuminates the roadway sign.

52. An automotive light according to claim 51 wherein the controller controls the light providing regions so that intensity of light they provide to illuminate signs farther from the vehicle is greater than intensity of light they provide to illuminate signs closer to the vehicle.

53. An automotive light according to claim 52 wherein intensity of light provided by the light providing regions to illuminate a road sign is substantially proportional to the square of a distance of the sign from the vehicle.

54. An automotive light according to any of claims 42-53 wherein the photosensor is sensitive to color and the light providing regions are controllable to provide different color light and wherein the controller process an image of the sign to determine its color components and controls hue and saturation of light that illuminates the sign to enhance its readability.

55. An automotive light according to any of claims 43-54 wherein the controller controls the light providing regions to radiate a train of light pulses and following each light pulse the controller gates on the photosurface for a short gate timed with respect to a time at which the light pulse is radiated and having a gate width so that light received by the photosurface during the gate is substantially only light reflected from matter in the air in a small volume of space located a short distance immediately in front of the illumination system and wherein the controller uses an amount of light received by the photosurface during the gates to determine visibility of the atmosphere.

56. An automotive light according to claim 55 wherein the controller adjusts illumination provided by the illumination system responsive to the determined visibility.

57. An automotive light according to claim 55 or claim 56 wherein light providing regions of the illuminator are controllable to provide visible light at different wavelengths and the controller determines visibility as a function of wavelength.

58. An automotive light according to claim 57 wherein the controller adjusts wavelength of visible light provided by the light providing regions to maximize visibility.

59. An automotive light according to any of claims 43-58 wherein the controller controls the 3D range-camera to repeatedly acquire an image of the roadway scene and determine distances to regions of the roadway scene at a frequency equal to or greater than 25 Hz.

60. An automotive light according to claim 59 wherein the frequency at which images are taken is a function of speed at which the vehicle is traveling.

61. An automotive light according claim 59 or claim 60 wherein following the acquisition of each image, the controller adjusts light provided by the light providing regions to match changes in the positions of one or both of features and objects in the roadway scene relative to their positions in an immediately preceding image of the roadway scene.

62. An automotive light according to any of claims 43-58 wherein following the acquisition of each image, the controller adjusts light provided by the light providing regions to match changes in the positions of one or both of features and objects in the scene relative to their positions in an immediately preceding image of the scene.

63. An automotive light according to claim 62 wherein a time lapse between acquisition of the image and a time at which the illuminator provides light adjusted responsive to the image is sufficiently short so that during the time lapse the positions of features and/or objects of the roadway scene do not change sufficiently to generate a substantial mismatch between the illumination and the scene.

64. An automotive light according to claim 63 wherein the time lapse is less than about 50 milliseconds.

65. An automotive light according to claim 63 wherein the time lapse is less than about 25 milliseconds.

66. An automotive light according to any of claims 43-65 wherein the automotive light is a headlight.

67. An automotive light according to claim 66 wherein the controller process images provided by the photosurface to identify oncoming vehicles and when an oncoming vehicle is identified, the controller controls the light providing regions to prevent blinding the driver of the oncoming vehicle.

68. An automotive light according to any of claims 43-65 wherein the automotive light is a tail light.

69. A light bulb comprising an illumination system according to any of claims 1-42.

70. A light bulb according to claim 69 adapted to be installed in a conventional light bulb socket.

72. A visual surveillance system comprising an illumination system according to any of claims 1-42 or claim 71 that illuminates a zone intended for visual surveillance by a watchman.

73. A visual surveillance system according to claim 72 wherein the controller controls the range finder to repeatedly image the surveillance zone and processes the images to determine presence of a person in the surveillance zone.

74. A visual surveillance system according to claim 73 wherein if the controller determines that a person is present in the surveillance zone the controller controls the light providing regions to generate an optical cue to alert the watchman to the person'"'"'s presence.

71. An illumination system for illuminating a scene, comprising:

an illuminator having a plurality of substantially contiguous independently controllable light providing regions each of which provides light that illuminates a different region of the scene;

optics that directs light from the illuminator to the scene;

a photosurface having pixels that is boresighted with the optics and the illuminator; and

a controller;

wherein the controller controls the photosurface to acquire an image the scene and controls the light providing regions of the illuminator responsive to the image.

75. An automotive light for use in a vehicle for illuminating a roadway scene comprising a portion of a road on which the vehicle is located and neighboring regions thereof the automotive light comprising:

an illuminator having a plurality of substantially contiguous independently controllable light providing regions each of which provides light that illuminates a different region of the scene;

optics that directs light from the illuminator to the scene;

a photosurface having pixels; and

a controller;

wherein the controller controls the photosurface to acquire an image the roadway scene and controls the light providing regions of the illuminator responsive to the image.