Non-circular aperture stop

• US 6,538,827 B2
• Filed: 03/06/2001
• Issued: 03/25/2003
• Est. Priority Date: 03/09/2000
• Status: Expired due to Fees

• Current Assignee: Donnelly Corporation (Magna International Incorporated)
• Original Assignee: Donnelly Corporation (Magna International Incorporated)
• Inventors: Bos, Brent J.
• Primary Examiner(s): Epps, Georgia
• Assistant Examiner(s): Thompson, Tim
• Application Number:
  US09/799,993
• Publication Number:
  US 20030021041A1
• Time in Patent Office: 749 Days
• Field of Search: 359/740, 359/739, 359/738, 348/148, 348/149, 348/117, 348/118, 348/113, 348/114, 348/115
• US Class Current: 359/740
• CPC Class Codes: B60R 1/00 Optical viewing arrangements; Real-time viewing arrangements for drivers or passengers using optical image capturing systems, e.g. cameras or video systems specially adapted for use in or on vehicles
• CPC Class Codes: B60R 1/26 to the rear of the vehicle
• CPC Class Codes: B60R 2300/101 using cameras with adjustable capturing direction
• CPC Class Codes: B60R 2300/8053 for bad weather conditions or night vision
• CPC Class Codes: B60R 2300/8066 for monitoring rearward traffic
• CPC Class Codes: G02B 5/005 Diaphragms for cameras G03B9/02

Abstract

A vision system for a vehicle includes an image capture device, a non-circular aperture stop and a display system. The image capture device is adapted to receive an image of a scene occurring exteriorly of the vehicle. The non-circular aperture stop defines a non-circular aperture and is positioned along an optical path between the scene and said image capture device. The display is operable to display an image from an output of said image capture device. The shape of the non-circular aperture is selected to enhance image sharpness along at least one axis of the image being received by the image capture device, while allowing sufficient light entry into the system for effective nighttime driving conditions.

Claims

1. A vision system for a vehicle comprising:

an image capture device which is adapted to receive an image of a scene occurring exteriorly of the vehicle;

a non-circular aperture stop positioned along an optical path between the scene and said image capture device, said non-circular aperture stop providing a non-circular aperture through which the image of the scene passes;

a display system which displays an image from an output of said image capture device; and

a reflective element adapted to be mounted on a portion of the vehicle for reflecting an image of the scene occurring exteriorly of the vehicle, said non-circular aperture stop being postioned along the optical path between said reflective element and said image capture device, wherein said reflective element has a first radius of curvature and a second radius of curvature, said first radius of curvature being different than said second radius of curvature.

2. A vision system for a vehicle comprising:

an image capture device which is adapted to receive an image of a scene occurring exteriorly of the vehicle;

a non-circular aperture stop postioned along an optical path between the scene and said image capture device, said non-circular aperture stop providing a non-circular aperture through which the image of the scene passes;

a display system which displays an image from an output of said image capture device; and

a reflective element adapted to be mounted on a portion of the vehicle for reflecting an image of the scene occurring exteriorly of the vehicle, said non-circular aperture stop being positioned along the optical path between said reflective element and said image capture device, wherein said reflective element reflects a non-rotationally symmetrical image toward said image capture device.

3. The vision system of claim 2, wherein said non-circular aperture comprises an elliptical aperture.

4. The vision system of claim 3, wherein said elliptical aperture has a first axis and a second axis, said first axis being larger than said second axis, said reflective element having a first radius of curvature and a second radius of curvature, said first radius of curvature being greater than said second radius of curvature, said first axis being generally aligned with a first plane defined by said first radius of curvature and said second axis being generally aligned with a second plane defined by said second radius of curvature.

5. The vision system of claim 4 further including a correcting optic positioned along the optical path between the scene and said image capture device.

6. The vision system of claim 5, wherein said correcting optic includes a diffractive element.

7. The vision system of claim 5, wherein said correcting optic includes a refractive element.

8. The vision system of claim 3, wherein said elliptical aperture has a first axis and a second axis, said first axis being larger than said second axis, said reflective element having a first radius of curvature and a second radius of curvature, said second radius of curvature being greater than said first radius of curvature, said first axis being generally aligned with a first plane defined by said first radius of curvature and said second axis being generally aligned with a second plane defined by said second radius of curvature.

9. The vision system of claim 8 further including a correcting optic positioned along the optical path between the scene and said image capture device.

10. The vision system of claim 9, wherein said correcting optic includes at least one of a diffractive element and a refractive element.

11. A vision system for a vehicle comprising:

an image capture device which is adapted to receive an image of a scene occurring exteriorly of the vehicle;

a non-circular aperture stop postioned along an optical path between the scene and said image capture device, said non-circular aperture stop providing a non-circular aperture through which the image of the scene passes;

a display system which displays an image from an output of said image capture device; and

a non-symmetrical reflective element positionable on a portion of the vehicle for reflecting an image for the scene occurring exteriorly of the vehicle toward said image capture device.

12. The vision system of claim 11, wherein said non-circular aperture stop is positioned between said non-symmetrical reflective element and said image capture device.

13. The vision system of claim 12, wherein said non-circular aperture is non-symmetrical.

14. The vision system of claim 13, wherein a shape of said non-symmetrical aperture is selected in response to a degree of astigmatism and aberrations in the reflected image.

15. The vision system of claim 14, wherein a reflective surface of said non-symmetrical reflective element is defined by one or more polynomial equations, said non-symmetrical aperture being defined in response to the shape of said reflective surface.

16. The vision system of claim 12 further including a correcting optic positioned along the optical path between said non-symmetrical reflective element and said image capture device.

17. The vision system of claim 12 further including a second reflective element positioned in an optic path from said non-symmetrical reflective element to said image capture device and adapted to redirect the reflected image toward said image capture device.

18. The vision system of claim 17, wherein said non-circular aperture stop is positioned along the optical path between said second reflective element and said image capture device.

19. The vision system of claim 18 further including a correcting optic positioned along the optical path between said second reflective element and said image capture device.

20. The vision system of claim 19, wherein said non-circular aperture stop is positioned between said correcting optic and said image capture device.

21. The vision system of claim 19, wherein said non-circular aperture stop is positioned between said correcting optic and the scene.

22. The vision system of claim 19, wherein said correcting optic includes at least one of a diffractive element and a refractive element.

23. A vision system for a vehicle comprising:

an image capture device which is adapted to receive an image of a scene occurring exteriorly of the vehicle;

a non-circular aperture stop positioned along an optical path between the scene and said image capture device, said non-circular aperture stop providing a non-circular aperture through which the image of the scene passes; and

a display system which displays an image from an output of said image capture device, wherein the image being received by said image capture device is received as at least one blur spot, said non-circular aperture being oriented with respect to said image capture device in response to a shape and orientation of the at least one blur spot being received by said image capture device.

24. The vision system of claim 23, wherein said non-circular aperture has a first axis and a second axis, said first axis being larger than said second axis, the at least one blur spot having a greater axis of aberration and a lesser axis of aberration, said non-circular aperture stop being oriented with respect to said image capture device to generally align at least one of said first and second axes with at least one of the greater and lesser axes of aberration of the at least one blur spot.

25. The vision system of claim 24, wherein said non-circular aperture stop is oriented with respect to said image capture device such that said first axis is generally aligned with the lesser axis of aberration of the at least one blur spot and said second axis is generally aligned with the greater axis of aberration of the at least one blur spot.

26. The vision system of claim 24, wherein said non-circular aperture stop is oriented with respect to said image capture device such that said first axis is generally aligned with the greater axis of aberration of the at least one blur spot and said second axis is generally aligned with the lesser axis of aberration of the at least one blur spot.

27. The vision system of claim 24, wherein said first and second axes are generally orthogonal to one another, the greater and lesser axes of aberration of the at least one blur spot being generally orthogonal to one another.

28. The vision system of claim 23 further comprising a reflective element adapted to be mounted on a portion of the vehicle for reflecting an image of the scene occurring exteriorly of the vehicle.

29. The vision system of claim 28, wherein said non-circular aperture stop is postioned along the optical path between said reflective element and said image capture device.

30. A vision system for a vehicle, comprising:

an image capture device which is adapted to receive an image of a scene occurring exteriorly of the vehicle;

a reflective element adapted to be mounted on a portion of the vehicle and configured to reflect a non-rotationally symmetrical image of the scene occurring exteriorly of the vehicle toward said image capture device;

a non-circular aperture stop positioned along an optical path between said reflective element and said image capture device, said non-circular aperture stop defining a non-circular aperture through which the reflected image passes; and

a display system which displays an image from an output of said image capture device.

31. The vision system of claim 30, wherein said non-circular aperture stop comprises an elliptical aperture stop defining an elliptical aperture having a first axis and a second axis, said first axis being larger than said second axis.

32. The vision system of claim 31, wherein said reflective element has a first radius of curvature defining a first plane and a second radius of curvature defining a second plane, said first radius of curvature being greater than said second radius of curvature.

33. The vision system of claim 32, wherein said first axis of said elliptical aperture is generally aligned with said first plane defined by said first radius of curvature and said second axis of said elliptical aperture is generally aligned with said second plane defined by said second radius of curvature.

34. The vision system of claim 33 further including a correcting optic positioned along the optical path between said reflective element and said image capture device.

35. The vision system of claim 34, wherein said correcting optic includes at least one of a diffractive element and a refractive element.

36. The vision system of claim 34 further including a second reflective element positioned in an optic path from said reflective element to said image capture device and adapted to redirect the reflected image toward said image capture device.

37. The vision system of claim 36, wherein said non-circular aperture is positioned along the optical path between said second reflective element and said image capture device.

38. The vision system of claim 32, wherein said first axis of said elliptical aperture is generally aligned with said second plane defined by said second radius of curvature and said second axis of said elliptical aperture is generally aligned with said first plane defined by said first radius of curvature.

39. The vision system of claim 38 further including a correcting optic positioned along the optical path between said reflective element and said image capture device.

40. The vision system of claim 39, wherein said correcting optic includes at least one of a diffractive element and a refractive element.

41. The vision system of claim 38 further including a second reflective element positioned in an optic path from said reflective element to said image capture device and adapted to redirect the reflected image toward said image capture device.

42. The vision system of claim 41, wherein said non-circular aperture is positioned along the optical path between said second reflective element and said image capture device.

43. The vision system of claim 30, wherein said reflective element comprises a non-rotationally symmetrical reflective element.

44. The vision system of claim 43, wherein said non-circular aperture stop comprises a non-symmetrical, non-circular aperture.

45. The vision system of claim 44, wherein a shape of said non-symmetrical, non-circular aperture is selected in response to a degree of astigmatism and aberration in the reflected image.

46. The vision system of claim 44, wherein a shape of said non-symmetrical, non-circular aperture is selected in response to at least one equation defining a surface of said non-rotationally symmetrical reflective element.