OPTICAL RANGEFINDER AND IMAGING APPARATUS WITH CHIRAL OPTICAL ARRANGEMENT

• US 20120069320A1
• Filed: 01/08/2010
• Published: 03/22/2012
• Est. Priority Date: 01/09/2009
• Status: Active Grant

• Current Assignee: M.C. Rombach Holding B.V.
• Original Assignee: Asmr Holding B.V.
• Inventors: Rombach, Michiel Christiaan, SImonov, Aleksey Nikolaevich
• Granted Patent: US 8,941,818 B2
• Time in Patent Office: Days
• US Class Current: 356/4.04
• CPC Class Codes: G01C 3/08 Use of electric radiation detectors
• CPC Class Codes: G01C 3/32 by focusing the object, e.g. on a ground glass screen

Abstract

An optical rangefinder having a photosensor adapted to transform the image projected thereon into an electronic image, an imaging system for projecting an image of an object on the photosensor, an optical arrangement to modulate the incoming light forming the image on the photosensor, means for providing the spatial spectrum of the image and means for deriving the distance from the object to the rangefinder on the degree of defocus of the image, wherein the optical arrangement is adapted to modulate the incoming light such that the degree of defocus of the image on the photosensor relative to the in-focus image plane results in displacement of the spatial spectrum of the image relative to a reference pattern and wherein the rangefinder has means for deriving the degree of defocus from the degree of displacement.

Claims

1. An optical rangefinder, comprising:

a) a photosensor adapted to transform the image projected onto it into a corresponding electronic image;

b) an imaging system adapted to project an image of at least one object on the photosensor, and at least one optical arrangement to modulate the incoming light beam forming the image on the photosensor;

c) spectral processing means adapted to provide the spatial spectrum of said image by spectral decomposition; and

d) defocus processing means adapted to derive the distance from the object to the rangefinder based on degree of defocus of the image,

wherein the optical arrangement is adapted to modulate the incoming light beam such that the degree of defocus of the image on the photosensor relative to the in-focus image plane results in displacement of the spatial spectrum of said image relative to a reference pattern, and the rangefinder comprises additional processing means adapted to directly derive the degree of defocus of the image of the object in the image plane relative to the in-focus image plane from said degree of displacement of the spatial spectrum relative to the reference pattern.

2. The optical rangefinder of claim 1, wherein the optical arrangement includes at least one chiral optical arrangement adapted to provide a degree of displacement of the spatial spectrum depending on the degree of defocus of the image.

3. The chiral optical rangefinder of claim, 2, wherein the chiral optical arrangement includes at least one chiral optical mask.

4. The optical rangefinder of claim 1, wherein the optical arrangement is a combination of at least two independent optical channels.

5. The combination of at the least two independent optical channels of claim 4, wherein the combination is adapted to provide chiral modulation.

6. The optical rangefinder of claim 1, wherein the optical arrangement is adapted to provide rotation of the spatial spectrum of the image relative to the reference pattern.

7. The optical rangefinder of claim 1, wherein the optical arrangement is adapted to provide scaling of the spatial spectrum of the image relative to the reference pattern.

8. The optical rangefinder of claim 1, wherein the optical arrangement is adapted to provide lateral shift of the spatial spectrum of the image relative to the reference pattern.

9. The optical rangefinder of claim 1, wherein the optical arrangement is adapted to provide at least one characteristic pattern in the spatial spectrum.

10. The optical rangefinder of claim 9, wherein the characteristic pattern includes the inherent spectral response of the optical arrangement.

11. The optical range finder of claim 10, wherein the characteristic pattern is a pattern of lines.

12. The optical rangefinder of claim 1, wherein the rangefinder is adapted to provide the degrees of defocus of at least two sub-images from corresponding sub-areas of the image.

13. The optical rangefinder of claim 12, wherein the rangefinder is adapted to provide a defocus map.

14. The optical rangefinder of claim 12, wherein the rangefinder is adapted to provide a depth map.

15. The optical rangefinder of claim 12, wherein the rangefinder is adapted to provide a wavefront map.

16. An image reconstructor having an optical rangefinder according to claim 1, comprising a photosensor adapted to transform the image projected onto it into a corresponding electronic image;

an imaging system adapted to project an image of at least one object on the photosensor, and at least one optical arrangement to modulate the incoming light beam forming the image on the photosensor;

spectral processing means adapted to provide the spatial spectrum of said image by spectral decomposition; and

defocus processing means adapted to derive the distance from the object to the rangefinder based on degree of defocus of the image,

wherein the optical arrangement is adapted to modulate the incoming light beam such that the degree of defocus of the image on the photosensor relative to the in-focus image plane results in displacement of the spatial spectrum of said image relative to a reference pattern, and the rangefinder comprises additional processing means adapted to directly derive the degree of defocus of the image of the object in the image plane relative to the in-focus image plane from said degree of displacement of the spatial spectrum relative to the reference pattern, and

wherein the image reconstructor is adapted to provide reconstruction of at least one in-focus image of the object from the spatial spectrum of the image.

17. The image reconstructor of claim 16, wherein the image reconstructor includes at least one chiral optical arrangement for imaging.

18. The image reconstructor of claim 17, wherein the chiral optical arrangement for imaging includes at least one parabolic chiral optical arrangement.

19. The image reconstructor of claim 18, wherein the parabolic chiral optical arrangement includes at least one parabolic chiral optical mask.

20. A phase diversity apparatus including an optical rangefinder, the phase diversity apparatus comprising:

a) an optical rangefinder according to claim 1 having a photosensor adapted to transform the image projected onto it into a corresponding electronic image;

an imaging system adapted to project an image of at least one object on the photosensor, and at least one optical arrangement to modulate the incoming light beam forming the image on the photosensor;

spectral processing means adapted to provide the spatial spectrum of said image by spectral decomposition; and

defocus processing means adapted to derive the distance from the object to the rangefinder based on degree of defocus of the image, wherein the optical arrangement is adapted to modulate the incoming light beam such that the degree of defocus of the image on the photosensor relative to the in-focus image plane results in displacement of the spatial spectrum of said image relative to a reference pattern, and the rangefinder comprises additional processing means adapted to directly derive the degree of defocus of the image of the object in the image plane relative to the in-focus image plane from said degree of displacement of the spatial spectrum relative to the reference pattern; and

b) additional means adapted to provide simultaneous processing of multiple images with known a priori defocus diversity.

21. The phase diversity apparatus including optical rangefinder of claim 20, wherein the phase diversity apparatus comprises an image reconstructor and additional means adapted to provide simultaneous processing of multiple images with known a priori defocus diversity.

22. The phase diversity apparatus of claim 20, wherein the phase diversity apparatus is an image reconstructor.

23. The phase diversity apparatus of claim 20, wherein the phase diversity apparatus is an optical rangefinder.

24. An optical pathfinder, comprising:

a) an optical rangefinder having a photosensor adapted to transform the image projected onto it into a corresponding electronic image and also having additional processing means adapted to directly derive the degree of defocus of the image of the object in the image plane relative to the in-focus image plane from said degree of displacement of the spatial spectrum relative to the reference pattern;

b) an imaging system adapted to project an image of at least one object on the photosensor, and having at least one optical arrangement to modulate the incoming light beam forming the image on the photosensor;

c) spectral processing means adapted to provide the spatial spectrum of said image by spectral decomposition;

d) defocus processing means adapted to derive the distance from the object to the rangefinder based on degree of defocus of the image, wherein the optical arrangement is adapted to modulate the incoming light beam such that the degree of defocus of the image on the photosensor relative to the in-focus image plane results in displacement of the spatial spectrum of said image relative to a reference pattern; and

e) means adapted to provide an estimate of at least one optical path.

25. A modal wavefront sensor, comprising:

a) a photosensor adapted to transform the image projected onto it into a corresponding electronic image;

b) an imaging system adapted to project an image of at least one object on the photosensor, and at least one optical arrangement to modulate the incoming light beam forming the image on the photosensor

c) spectral processing means adapted to provide the spatial spectrum of said image by spectral decomposition; and

d) defocus processing means adapted to derive the distance from the object to the rangefinder based on degree of defocus of the image,

wherein the optical arrangement is adapted to modulate the incoming light beam such that least one wavefront aberration results in displacement of the spatial spectrum of said image relative to a reference pattern, and that the rangefinder comprises additional processing means adapted to directly derive the degree of at least one wavefront aberration of the image of the object in the image plane relative to the in-focus image plane from said degree of displacement of the spatial spectrum relative to the reference pattern.

26. A method for optical rangefinding, comprising:

a) projecting an image of at least one object on a photosensor;

b) modulating the incoming light beam by an optical arrangement;

c) processing the image projected on the photosensor into a corresponding electronic image, providing the spatial spectrum of an image by spectral decomposition; and

d) deriving the distance from the object to the rangefinder based on degree of defocus of the image,

e) modulating the incoming light beam such that defocus of the image of the at least one object in the image plane relative to the in-focus image plane results in a displacement of the spatial spectrum of the image relative to the reference pattern, and

f) deriving the degree of defocus of the image of the object in the image plane relative to the in-focus image plane from said degree of displacement of the spatial spectrum relative to the reference pattern.

27. The method for optical rangefinding of claim 26, wherein the modulation of the light beam is a chiral modulation such that the degree of displacement of the spatial spectrum relative to the reference pattern depends on the degree of defocus of the image.

28. The method for optical rangefinding of claim 26, wherein modulation of the light beam is such that at least one characteristic pattern in the spatial spectrum is provided.

29. A method for image reconstruction, wherein the method for image reconstruction is a combination of methods according to claim 28 and further comprising processing steps adapted to reconstruct at least one in-focus image of the object from the spatial spectrum of the image.

30. A method for optical rangefinding according to claim 29, wherein the method for optical rangefinding is adapted to provide at least one optical path.

31. A method for modal wavefront sensing, comprising:

a) projecting an image of at least one object on a photosensor;

b) modulating the incoming light beam by an optical arrangement;

c) processing to transform the image into a corresponding electronic image; and

d) providing the spatial spectrum of the image by spectral decomposition,

e) modulating through adapting the incoming light beam such that at least one wavefront aberration results in at least one displacement of the spatial spectrum of the image relative to a reference pattern, and

f) deriving the degree of at least one wavefront aberration from said degree of displacement of the spatial spectrum relative to the reference pattern.