Intelligent electro-optical system and method for automatic glare reduction

• US 5,305,012 A
• Filed: 04/15/1992
• Issued: 04/19/1994
• Est. Priority Date: 04/15/1992
• Status: Expired due to Term

• Current Assignee: Reveo, Inc.
• Original Assignee: Reveo, Inc.
• Inventors: Faris, Sadeg M.
• Primary Examiner(s): Oberley, Alvin E.
• Assistant Examiner(s): Saras, Steven J.
• Application Number:
  US07/869,566
• Time in Patent Office: 734 Days
• Field of Search: 340/705, 340/784, 340/980, 358/103, 359/38, 359/601, 359/630, 359/230, 364/449, 382/1, 345/7, 345/8, 345/9, 345/84, 345/105
• US Class Current: 345/7
• CPC Class Codes: A61F 9/023 with variable transmission, e.g. photochromic for welding A61F9/067
• CPC Class Codes: B60J 3/02 adjustable in position B60J3/002, B60J3/005 take precedence
• CPC Class Codes: G02C 7/101 having an electro-optical light valve electro-optical elements per se G02F
• CPC Class Codes: G02F 1/13318 Circuits comprising a photodetector

Abstract

An electro-optical system and method are disclosed for modulating the intensity of light rays propagating towards an optical element, such as an eye, a lens or aperture stop in a camera station, a camera station in a machine vision system, or other image detection device. The electro-optical system comprises an electro-optical element having a optically transparent surface having electrically addressable pixels. Each pixel has a light transmittance which is controllable by a controller that is operably associated with a computer system. An image acquisition device, such as a camera station, acquires an image of a spatial scene within the field of view of the optical element. The computer system processes the image to determine which pixels are to be addressed and actively driven in order to modulate (i.e. decrease) the intensity of incident light rays propagating through the determined pixels, towards the optical element. Illustrated uses for the present invention include glare and spatial noise reduction in the automotive, navigational, robotic and recreational arts.

Claims

1. Apparatus for automatically reducing glare produced from a three-dimensional spatial scene by reducing the intensity of light rays propagating from points in the three-dimensional spatial scene towards an optical element having a field of view, said apparatus comprising:

an electro-optical element having an optically transparent surface including a plurality of pixels through which the field of view of said optical element passes, each said pixel having a controllable light transmittance for selectively reducing the intensity of incident light rays propagating from one or more points in the three-dimensional spatial scene, through said pixel, then towards said optical element;

image acquisition means for acquiring one or more images of said three-dimensional spatial scene within the field of view of said optical element;

image processing means for processing said one or more acquired images and determining at which pixels the light transmittance is to be actively controlled in order to reduce the intensity of incident light rays by a selected amount before reaching said optical element; and

control means for actively controlling the light transmittance of the determined pixels so that after incident light rays propagate through said determined pixels, said incident light rays propagate towards said optical element with an intensity reduced by said selected amount, so that glare produced from the three-dimensional spatial scene is automatically reduced.

2. The apparatus of claim 1, wherein said control means comprises means for electrically addressing and driving said determined pixels, and wherein the light transmittance of each said pixel is independently controllable.

3. The apparatus of claim 2, which further comprises an optical element tracking means for determining the position of said optical element with respect to said electro-optical element, and wherein said image acquisition means is stationarily positioned with respect to said electro-optical element.

4. The apparatus of claim 1, wherein said electro-optical element comprises an electrically addressable liquid crystal light valve, and wherein the light transmittance of each said pixel is independently controllable.

5. The apparatus of claim 4, wherein said optical element is the pupil of an eye which is free to move relative to said electro-optical element.

6. The apparatus of claim 5, which further comprises means for installing said electro-optical element above the dashboard of an automotive vehicle.

7. The apparatus of claim 2, which further comprises an optical element tracking means for determining the position of said optical element with respect to said electro-optical element, and wherein said image acquisition means is stationarily positionable with respect to said electro-optical element.

8. The apparatus of claim 7, wherein said electro-optical element comprises an electrically addressable liquid crystal light valve.

9. The apparatus of claim 8, wherein said optical element is the pupil of an eye which is free to move relative to said optical element.

10. The apparatus of claim 9, which further comprises means for installing said electro-optical element above the dashboard of an automotive vehicle.

11. The apparatus of claim 2, wherein said electro-optical element and said image acquisition means are stationarily positioned with respect to said optical element.

12. The apparatus of claim 11, wherein said optical element is the left and right eyes of a person, and wherein said electro-optical element comprises first and second electrically addressable liquid crystal light valve panels stationarily positionable with respect to said left and right eyes.

13. The apparatus of claim 1, wherein said electro-optical element further comprises a reflective layer adjacent said optically transparent surface so as to reflect incident light rays from behind said optically transparent surface.

14. The apparatus of claim 13, which further comprises an optical element tracking means for determining the position of said optical element with respect to said electro-optical element, and wherein said image acquisition means is stationarily positioned with respect to said electro-optical element.

15. The apparatus of claim 14, wherein said electro-optical element comprises an electrically addressable liquid crystal light valve surface.

16. The apparatus of claim 15, wherein said optical element is the pupil of an eye which is free to move relative to said electro-optical element.

17. The apparatus of claim 16, which further comprises means for installing said electro-optical element above the dashboard of an automotive vehicle.

18. The apparatus of claim 13, which further comprises an optical element tracking means for determining the position of said optical element with respect to said electro-optical element, and wherein said image acquisition means is stationarily positionable with respect to said electro-optical element.

19. The apparatus of claim 18, wherein said electro-optical element comprises an electrically addressable liquid crystal light valve surface.

20. The apparatus of claim 19, wherein said optical element is the pupil of an eye which is free to move relative to said optical element.

21. The apparatus of claim 20, which further comprises means for installing said electro-optical element above the dashboard of an automotive vehicle.

22. The apparatus of claim 13, wherein said electro-optical element and said image acquisition means are stationarily positioned with respect to said optical element.

23. A method for automatically reducing glare produced from a three-dimensional spatial scene by reducing the intensity of light rays propagating from points in the three-dimensional spatial scene towards an optical element having a field of view, said method comprising the steps:

a) providing an elector-optical element at a desired distance from said optical element so that the field of view of said optical element passes through said electro-optical element and in the direction of the three-dimensional spatial scene, said electro-optical element having an optically transparent surface including a plurality of pixels, each said pixel having an controllable light transmittance for selectively reducing the intensity of incident light rays propagating from one or more points in said three-dimensional spatial scene, through said pixel, then towards said optical element;

b) acquiring one or more images of said three-dimensional spatial scene within the field of view of said optical element;

c) processing said one or more acquired images so as to determine at which pixels the light transmittance is to be actively controlled in order to reduce the intensity of incident light rays by a selected amount before said incident light rays reach said optical element; and

d) actively controlling the light transmittance of said determined pixels so that after incident light rays propagate through said determined pixels, the incident light rays propagate towards said optical element with an intensity reduced by said selected amount, so that glare produced from points in the three-dimensional spatial scene is automatically reduced.

24. The electro-optical system of claim 23, wherein said control means comprises means for electrically addressing and driving said determined pixels, and wherein the light transmittance of each said pixel is independently controllable.

25. The electro-optical system of claim 23, wherein said electro-optical element comprises an electrically addressable liquid crystal light valve, and wherein the light transmittance of each said pixel is independently controllable.

26. The electro-optical system of claim 23, which further comprises eye-tracking means for determining the position of the eyes of the driver with respect to said electro-optical element, and wherein said image acquisition means is stationarily positionable with respect to said electro-optical element.

27. The electro-optical system of claim 26, wherein said electro-optical element comprises an electrically addressable liquid crystal light valve.

28. The electro-optical system of claim 23, wherein said electro-optical element and said image acquisition means are stationarily positionable with resect to the eyes of the driver.

29. The electro-optical system of claim 28, wherein said electro-optical element comprises an electrically addressable liquid crystal light valve, and wherein the light transmittance of each said pixel is independently controllable.

30. The electro-optical system of claim 23, wherein said electro-optical element comprises first and second electrically addressable liquid crystal light valve panels stationarily positionable with respect to the left and right eyes of the driver.

31. The electro-optical system of claim 30, wherein the light transmittance of each said pixel is independently controllable.

32. The electro-optical system of claim 23, wherein said electro-optical element further comprises a reflective layer adjacent said optically transparent surface so as to reflect incident light rays from behind said optically transparent surface.

33. The electro-optical system of claim 23, which further comprises eye-tracking means for determining the position of the eyes of the driver with respect to said electro-optical element, and wherein said image acquisition means is stationarily positionable with respect to said electro-optical element, and wherein the light transmittance of each said pixel is independently controllable.

34. The electro-optical system of claim 31, wherein said electro-optical elements comprises an electrically addressable liquid crystal light valve.

35. The electro-optical system of claim 23, wherein said image acquisition means comprises a CCD image detecting array.

36. The electro-optical system of claim 26, wherein said eye-tracking means comprises a CCd image detecting array.

37. The electro-optical system of claim 33, wherein said eye-tracking means comprises a CCD image detecting array.

38. An electro-optical system for automatically reducing glare produced from a three-dimensional spatial scene by reducing the intensity of light rays propagating from points in the three-dimensional spatial scene towards the eyes of a driver having a field of view from aboard a vehicle, said electro-optical system comprising:

an electro-optical element mounted aboard the vehicle and having an optically transparent surface including a plurality of pixels through which the field of view of the eyes of the driver passes, each said pixel having an controllable light transmittance for selectively reducing the intensity of incident light rays propagating from one or more points in the three-dimensional spatial scene, through said pixel, then towards the eyes of the driver;

image acquisition means for acquiring one or more images of said three-dimensional spatial scene within the field of view of the eyes of the driver;

image processing means for processing said one or more acquired images and determining at which pixels the light transmittance is to be actively controlled in order to reduce the intensity of incident light rays by a selected amount before reaching the eyes of the driver; and

control means for actively controlling the light transmittance of said determined pixels so that after incident light rays propagate through said determined pixels, the incident light rays propagate towards the eyes of the driver with an intensity reduced by said selected amount, so that glare produced from the three-dimensional spatial scene is automatically reduced.

39. A method for automatically reducing glare produced from a three-dimensional spatial scene by reducing the intensity of light rays propagating from points in the three-dimensional spatial scene towards the eyes of a driver having a field of view from aboard a vehicle, sad method comprising the steps:

a) providing an electro-optical element at a desired distance from the eyes of the driver so that the field of view of the driver passes through said electro-optical element, said electro-optical element having an optically transparent surface including a plurality of pixels, each said pixel having a controllable light transmittance for selectively reducing the intensity of incident light rays propagating from one or more points in the three-dimensional spatial scene, through said pixel, then towards the eyes of the driver;

b) acquiring one or more images of the three-dimensional spatial scene within the field of view of the eyes of the driver;

c) processing said one or more acquired images so as to determine at which pixels the light transmittance is to be actively controlled in order to reduce the intensity of incident light rays by a selected amount before said incident light rays reach the eyes of the driver; and

d) actively controlling the light transmittance of said determined pixels so that after incident light rays propagate through said determined pixels, the incident light rays propagate towards the eyes of the driver with an intensity reduced by said selected amount, so that glare produced from the three-dimensional spatial scene is automatically reduced.

40. A method of claim 39, wherein step (d) further comprises independently controlling the light transmittance of each said determined pixel.

41. The method of claim 39, where in step (a) said electro-optical element comprises an electrically addressable liquid crystal light valve, and wherein the light transmittance of each said pixel is independently controlled.

42. The method of claim 41, wherein step (d) further comprises independently controlling the light transmittance of each said determined pixel.