Wide angle field of view active illumination imaging system

• US 8,988,508 B2
• Filed: 09/24/2010
• Issued: 03/24/2015
• Est. Priority Date: 09/24/2010
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Yahav, Giora, Cohen, David
• Primary Examiner(s): Perungavoor, Sath V
• Assistant Examiner(s): Brown, Jr., Howard D
• Application Number:
  US12/889,479
• Publication Number:
  US 20120075427A1
• Time in Patent Office: 1,642 Days
• Field of Search: 348/47
• US Class Current: 348/47
• CPC Class Codes: A63F 2300/1093 using visible light
• CPC Class Codes: G01S 17/87 Combinations of systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/894 3D imaging with simultaneous measurement of time-of-flight at a 2D array of receiver pixels, e.g. time-of-flight cameras or flash lidar
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06F 3/017 Gesture based interaction, e.g. based on a set of recognized hand gestures interaction based on gestures traced on a digitiser G06F3/04883
• CPC Class Codes: G06V 10/147 Details of sensors, e.g. sensor lenses fingerprint or palmprint sensors G06V40/13; vascular sensors G06V40/145; eye sensors G06V40/19
• CPC Class Codes: H04N 13/239 using two 2D image sensors having a relative position equal to or related to the interocular distance H04N13/243 takes precedence
• CPC Class Codes: H04N 13/243 using three or more 2D image sensors
• CPC Class Codes: H04N 13/254 in combination with electromagnetic radiation sources for illuminating objects
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/698 for achieving an enlarged field of view, e.g. panoramic image capture

Abstract

An embodiment of the invention provides an active illumination imaging system comprising a first camera and a second camera, each having an optical axis and a field of view (FOV) characterized by a view angle in a plane that contains the optical axis and wherein the optical axes of the cameras intersect at an intersection region common to their FOVs at an angle substantially equal to half a sum of their view angles.

Claims

1. An active illumination imaging system comprising:

a light source to illuminate a scene imaged by a camera; and

first and second cameras, each comprising an optical system having an optical axis and a photosensor having pixels on which the optical system is to imagine light, and a field of view (FOV) characterized by a view angle in a plane that contains the optical axis;

wherein the optical axes of the first and a second cameras intersect at an intersection region common to their FOVs at an angle substantially equal to half a sum of their view angles to provide the imaging system with an enlarged FOV having an enlarged view angle in a plane defined by the intersecting optical axes that is substantially equal to a sum of the view angles of the cameras, and in which, intersections of the FOVs of the cameras with the plane that are adjacent to each other, are substantially parallel.

2. The active illumination imaging system according to claim 1 wherein the view angles of the first and second cameras are equal.

3. The active illumination imaging system according to claim 1 wherein the view angles of the first and second cameras are not equal.

4. The active illumination imaging system according to claim 1 wherein the enlarged view angle is greater than or equal to 90°

.

5. The active illumination imaging system according to claim 4 wherein the enlarged view angle is greater than or equal to 120°

.

6. The active illumination imaging system according to claim 5 wherein the enlarged view angle is greater than or equal to 150°

.

7. The active illumination imaging system according to claim 1 and comprising a third camera whose optical axis intersects the optical axis of the second camera.

8. The active illumination imaging system according to claim 7 wherein a plane defined by the optical axes of the second and third cameras is substantially coincident with the plane defined by the optical axes of the first and second cameras.

9. The active illumination imaging system according to claim 8 wherein the axes of the second and third cameras intersect at an angle substantially equal to half a sum of the view angles of the second and third cameras.

10. The active illumination imaging system according to claim 7 wherein a plane defined by the optical axes of the second and third cameras is substantially perpendicular to the plane defined by the optical axes of the first and second cameras.

11. The active illumination imaging system according to claim 10 wherein the second camera has a view angle in the plane defined by the optical axes of the second and third cameras and the optical axes of the second and third cameras intersect at an angle substantially equal to half a sum of the view angle of the third camera plus the view angle of the second camera in the plane of the optical axes of the second and third cameras.

12. The active illumination imaging system according to claim 1 wherein the cameras are 3D cameras that provide distances to features in a scene that they image.

13. The active illumination imaging system according to claim 12 wherein the 3D cameras are time of flight cameras (TOF) cameras.

14. An imaging system comprising:

a first camera and a second camera, each having an optical axis and a field of view (FOV) characterized by a view angle in a plane that contains the optical axis;

wherein the optical axes of the cameras intersect at an intersection region common to their FOVs at an angle substantially equal to half a sum of their view angles to provide the imaging system with an enlarged FOV having an enlarged view angle in a plane defined by the intersecting optical axes that is substantially equal to a sum of the view angles of the cameras, and in which, intersections of the FOVs of the cameras with the plane that are adjacent to each other, are substantially parallel.

15. The imaging system according to claim 14 wherein a measure of the system'"'"'s sensitivity to light that it images is equal to a product of an average vignetting factor of the imaging system times a square of a quotient equal to a diameter of pixels in the imaging system divided by a minimum f# of imaging system, and the measure has a value greater than 20.

16. The imaging system according to claim 15 wherein the measure has a value greater than 50.

17. The imaging system according to claim 15 wherein the measure has a value greater than 100.

18. The imaging system according to claim 15 wherein the measure has a value greater than 120.

19. The imaging system according to claim 14 comprising an enlarged FOV having an enlarged view angle in a plane defined by the intersecting optical axes that is substantially equal to a sum of the view angles of the cameras.