Electromagnetic scanning imager

• US 8,593,157 B2
• Filed: 11/09/2009
• Issued: 11/26/2013
• Est. Priority Date: 02/15/2005
• Status: Active Grant

• Current Assignee: Walleye Technologies, Inc.
• Original Assignee: Walleye Technologies, Inc.
• Inventors: Adams, Christopher P., Holbrook, David S.
• Primary Examiner(s): Hollington, Jermele M
• Assistant Examiner(s): Rhodes-Vivour, Temilade S
• Application Number:
  US12/614,745
• Publication Number:
  US 20100109680A1
• Time in Patent Office: 1,478 Days
• Field of Search: 324/642, 324/22, 324/244.1, 324/750.23, 324/754.23, 324/542, 324/97, 342/22
• US Class Current: 324/642
• CPC Class Codes: G01R 27/04 in circuits having distributed constants , e.g. having very long conductors or involving high frequencies
• CPC Class Codes: G01S 13/426 Scanning radar, e.g. 3D radar G01S13/66 takes precedence
• CPC Class Codes: G01S 13/89 for mapping or imaging
• CPC Class Codes: H01Q 19/065 Zone plate type antennas

Abstract

In one aspect, the present invention provides an imager, preferably portable, that includes a source of electromagnetic radiation capable of generating radiation with one or more frequencies in a range of about 1 GHz to about 2000 GHz. An optical system that is optically coupled to the source focuses radiation received therefrom onto an object plane, and directs at least a portion of the focused radiation propagating back from the object plane onto an image plane. The imager further includes a scan mechanism coupled to the optical system for controlling thereof so as to move the focused radiation over the object plane. A detector optically coupled to the lens at the image plane detects at least a portion of the radiation propagating back from a plurality of scanned locations in the object plane, thereby generating a detection signal. A processor that is in communication with the detector generates an image of at least a portion of the object plane based on the detection signal.

Claims

1. An imaging system, comprising a housing adapted for positioning on a surface, said housing comprising:

a source of electromagnetic radiation for generating radiation with one or more frequencies in a range of about 1 GHz to about 2000 GHz,

an optical system optically coupled to said source so as to focus radiation received therefrom onto an object plane, said optical system directing at least a portion of the focused radiation propagating back from the object plane onto an image plane,

a scan mechanism coupled to the optical system for receiving radiation therefrom and/or directing radiation thereto, said scan mechanism effecting the scanning of the focused radiation over a two-dimensional portion of the object plane, said housing, optical system, and scan mechanism remaining translationally stationary relative to said surface as said scan mechanism effects the scanning of the radiation,

a detector optically coupled to said optical system at the image plane to detect at least a portion of the radiation propagating back from a plurality of scanned locations in the object plane, thereby generating a detection signal, and

a processor in communication with the detector to generate an image of at least a portion of the object plane based on said detection signal,

wherein said scan mechanism comprises two rotatable refractive elements and said refractive elements comprise a plurality of transmissive prisms, each of said prisms being configured to rotate about a respective rotation axis, and wherein said axes are perpendicular to the bisector of the respective vertex angles of said prisms.

2. The scan mechanism of claim 1, wherein the refractive elements are disposed optically in series.

3. The scan mechanism of claim 1, wherein the refractive elements comprise a two-dimensional raster scanner.

4. The scan mechanism of claim 1, wherein the refractive elements comprise a two-dimensional spiral scanner.

5. The scan mechanism of claim 1, wherein the refractive elements comprise a floret scanner.

6. The imaging system of claim 1, further comprising one or more position sensors coupled to said scan mechanism for determining a two-dimensional position thereof relative to a reference position.

7. The imaging system of claim 1, further comprising a display in communication with said processor for displaying said image.

8. The imaging system of claim 1, wherein said processor maps a variation of said detection signal to said scanned locations so as to generate said image.

9. The imaging system of claim 7, wherein for each image point coordinate corresponding to one of the scanned locations, the display presents a brightness proportional to a strength of the detection signal corresponding to back-propagating radiation from that scanned location.

10. The imaging system of claim 1, wherein said radiation source and said detector are formed as a single transmit/receive module operating in said frequency range of about 1 GHz to about 2000 GHz.

11. The imaging system of claim 1, wherein said housing is a portable housing.

12. The imaging system of claim 11, further comprising an electronic processor and display module (EPDM) that includes said processor.

13. The imaging system of claim 12, wherein said EPDM is integrated within said portable housing.

14. The imaging system of claim 13, further comprising a second housing, separate from the portable housing, for containing said EPDM, said second housing being in data or signal communication with said portable housing.

15. The imaging system of claim 12, wherein said EPDM comprises a display module for displaying said image.

16. The imaging system of claim 1, further comprising a mechanism coupled to the source for modulating frequency of radiation generated by the source.

17. The imaging system of claim 16, wherein said mechanism modulates the radiation frequency at a rate of about 100 kHz.

18. An imaging system, comprising a housing for positioning on a surface, said housing comprising:

a source of electromagnetic radiation for generating radiation with one or more frequencies in a range of about 1 GHz to about 2000 GHz,

an optical system optically coupled to said source so as to focus radiation received therefrom onto an object plane, said optical system directing at least a portion of the focused radiation propagating back from the object plane onto an image plane,

a scan mechanism coupled to the optical system for receiving radiation therefrom and/or directing radiation thereto, said scan mechanism effecting the scanning of the focused radiation over a two-dimensional portion of the object plane, said housing, optical system, and scan mechanism remaining translationally stationary relative to said surface as said scan mechanism effects the scanning of the radiation,

a detector optically coupled to said optical system at the image plane to detect at least a portion of the radiation propagating back from a plurality of scanned locations in the object plane, thereby generating a detection signal, and

a processor in communication with the detector to generate an image of at least a portion of the object plane based on said detection signal,

wherein said scan mechanism comprises a plurality of rotatable diffractive elements and

wherein said diffractive elements comprise a diffraction grating element and a binary Fresnel lens element, said elements being independently rotatable.

19. The imaging system of claim 18, further comprising one or more position sensors coupled to said scan mechanism for determining a two-dimensional position thereof relative to a reference position.

20. The imaging system of claim 18, further comprising a display in communication with said processor for displaying said image.

21. The imaging system of claim 18, wherein said processor maps a variation of said detection signal to said scanned locations so as to generate said image.

22. The imaging system of claim 21, wherein for each image point coordinate corresponding to one of the scanned locations, the display presents a brightness proportional to a strength of the detection signal corresponding to back-propagating radiation from that scanned location.

23. The imaging system of claim 18, wherein said radiation source and said detector are formed as a single transmit/receive module operating in said frequency range of about 1 GHz to about 2000 GHz.

24. The imaging system of claim 18, wherein said housing is a portable housing.

25. The imaging system of claim 24, further comprising an electronic processor and display module (EPDM) that includes said processor.

26. The imaging system of claim 25, wherein said EPDM is integrated within said portable housing.

27. The imaging system of claim 26, further comprising a second housing, separate from the portable housing, for containing said EPDM, said second housing being in data or signal communication with said portable housing.

28. The imaging system of claim 26, wherein said EPDM comprises a display module for displaying said image.

29. The imaging system of claim 18, further comprising a mechanism coupled to the source for modulating frequency of radiation generated by the source.

30. The imaging system of claim 29, wherein said mechanism modulates the radiation frequency at a rate of about 10 kHz.