Method of simultaneously applying multiple illumination schemes for simultaneous image acquisition in an imaging system

• US 20010030744A1
• Filed: 12/19/2000
• Published: 10/18/2001
• Est. Priority Date: 12/27/1999
• Status: Abandoned Application

• Current Assignee: OG Technologies, Inc.
• Original Assignee: OG Technologies, Inc.
• Inventors: Chang, Tzyy-Shuh
• Application Number:
  US09/740,270
• Publication Number:
  US 20010030744A1
• Time in Patent Office: Days
• US Class Current: 356/237.3
• CPC Class Codes: G01N 2021/8845 Multiple wavelengths of illumination or detection
• CPC Class Codes: G01N 21/8806 Specially adapted optical and illumination features

Abstract

A method is used for imaging applications so that one can simultaneously apply multiple illumination schemes and simultaneously acquire the images, each associated with one of the multiple illumination schemes. The illumination schemes can be, but not limited to, any combination of reflective illumination, transmitive illumination (backlighting), bright field illumination, dark field illumination, diffused illumination, cloudy-day illumination, and structured illumination. The radiation can be in any wavelengths, ranging from sonic waves, ultra sound, radio waves, microwaves, infrared, near infrared, visible light, ultra violet, X-rays, and gamma rays. The radiation of each of the illumination schemes used in an imaging application is modulated, that is, affixed with a unique signature. One or more imaging devices can be used to collect the radiating rays simultaneously after the rays interact with the object(s). The image signal(s) are then demodulated, separated into several images, each is associated with an illumination scheme, based on the signatures. A preferred embodiment is to use radiation wavelengths of 430 nm, 575 nm or 670 nm as the signatures.

Claims

1. A system for observing an object comprising:

a first radiation projector configured to produce a first radiation signal having a first wavelength;

a second radiation projector configured to produce a second radiation signal having a second wavelength different from said first wavelength;

an image acquisition device arranged to have the object in a field of view thereof and that is configured to simultaneously capture radiation signals having said first and second wavelengths to produce an image of the object; and

a controller configured to cause said first and second radiation projectors to simultaneously illuminate the object with said first and second radiation signals and control said image acquisition device to produce the image of the object in timed relation therewith.

2. The system of

claim 1

wherein said first and second wavelengths comprise one of audible sound wavelengths, ultrasound wavelengths, radio wavelengths, infrared wavelengths, visible light wavelengths, ultraviolet light wavelengths and X-ray wavelengths.

3. The system of

claim 1

wherein said first and second radiation projectors are coupled to a first light source by way of a waveguide.

4. The system of

claim 3

wherein said light guide comprises at least one of an optical fiber, a periscope and a sonic tube.

5. The system of

claim 1

wherein said first and second radiation projectors comprise a wideband source and respective interference or color filter selected so as to establish said first and second wavelength radiation signals.

6. The system of

claim 1

wherein said first and second radiation projectors comprise a respective radiation source that directly produces radiation having said first and second wavelengths, respectively.

7. The system of

claim 6

wherein said respective radiation sources comprises first and second lasers.

8. The system of

claim 1

wherein said image acquisition device comprises a color charge coupled device (CCD) camera.

9. The system of

claim 1

wherein said image acquisition device comprises a monochromatic camera.

10. The system of

claim 1

wherein said image acquisition device comprises a color camera having one CCD.

11. The system of

claim 10

wherein said color camera comprises a plurality of CCD chips.

12. The system of

claim 1

wherein said first and second radiation sources include means for adding said first and second wavelength signals to respective base radiation signals.

13. The signature adding process, as mentioned in

claim 12

, can be amplitude modulation.

14. The signature adding process, as mentioned in

claim 12

, can be frequency modulation.

15. The signature adding process, as mentioned in

claim 12

, can be phase-lock loops.

16. The system of

claim 12

wherein one of said first and second sources are arranged relative to said object and image acquisition device for dark field illumination.

17. The system of

claim 12

wherein one of said first and second sources are arranged relative to said object and image acquisition device for bright field illumination.

18. The system of

claim 12

wherein one of said first and second sources are arranged relative to said object and image acquisition device for transmitive illumination.

19. The system of

claim 12

wherein one of said first and second sources are arranged relative to said object and image acquisition device for structured illumination.

20. The system of

claim 12

wherein one of said first and second sources are arranged relative to said object and image acquisition device for cloudy-day illumination.

21. The system of

claim 12

wherein one of said first and second sources are arranged relative to said object and image acquisition device to detect surface anomalies on the surface(s) of the object(s) such as, but not limited to, nicks, scratches, polishes, foreign objects, and sculptures.

22. The system of

claim 12

wherein one of said first and second sources are arranged relative to said object and image acquisition device to detect surface discoloration on the surface(s) of the object(s), such as, but not limited to, colored marks, prints, and material differences.

23. The system of

claim 12

wherein one of said first and second sources are arranged relative to said object and image acquisition device to detect the boundaries and/or edges of (a) the object(s), and/or (b) the feature(s) on the object(s).

24. The system of

claim 12

wherein one of said first and second sources are arranged relative to said object and image acquisition device to detect the surface profile of the object(s).

25. The system of

claim 12

wherein one of said first and second sources are arranged relative to said object and image acquisition device to detect and verify the integrity of features on the object(s).

26. The system of

claim 1

wherein said controller is configured to modulate said radiation generated by said radiation projectors in such a way as to allow ambient light impinging on the object to be removed.