APPARATUS AND METHOD FOR MULTI-SPECTRAL DUAL BALANCED IMAGING

• US 20140354873A1
• Filed: 07/12/2012
• Published: 12/04/2014
• Est. Priority Date: 07/20/2011
• Status: Active Grant

• Current Assignee: Power Diagnostic Technologies Ltd.
• Original Assignee: Power Diagnostic Technologies Ltd.
• Inventors: Parsons, Robert
• Granted Patent: US 9,638,846 B2
• Time in Patent Office: Days
• US Class Current: 348/342
• CPC Class Codes: G01J 3/0208 using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction
• CPC Class Codes: G01J 3/0227 using notch filters
• CPC Class Codes: G01J 3/36 Investigating two or more bands of a spectrum by separate detectors
• CPC Class Codes: G02B 27/1013 for colour or multispectral image sensors, e.g. splitting an image into monochromatic image components on respective sensors spectral imaging systems G01J
• CPC Class Codes: G02B 5/26 Reflecting filters G02B5/28 takes precedence
• CPC Class Codes: H04N 23/11 for generating image signals from visible and infrared light wavelengths
• CPC Class Codes: H04N 25/671 for non-uniformity detection or correction

Abstract

An apparatus and method for multi-spectral dual balanced imaging is provided. The apparatus includes: (a) a first member operable to produce from incident light a first band having first band wavelengths and a second band; and (b) a second member operable to produce from the second band a third band having wavelengths shorter than the first band wavelengths, excluding the first band wavelengths and having wavelengths longer than the first band wavelengths. The method involves: (a) producing from incident light a first band having first band wavelengths and a second band; and (b) producing from the second band a third band having wavelengths shorter than the first band wavelengths, excluding the first band wavelengths and having wavelengths longer than the first band wavelengths.

Claims

1. An apparatus for multi-spectral balanced imaging, the apparatus comprising:

(a) a first member operable to produce from incident light a first band having first band wavelengths and a second band;

(b) a second member operable to produce from said second band a third band having wavelengths shorter than said first band wavelengths, excluding said first band wavelengths and having wavelengths longer than said first band wavelengths;

(c) a first detector for producing a first image by detecting said first band; and

(d) a second detector for producing a second image by detecting said third band after said third band has propagated from said second member to said second detector,

wherein a first intensity associated with said first band is substantially equal to a second intensity associated with said third band when said incident light is uniform.

2. The apparatus of claim 1 wherein said first member reflects said first band from said first member and transmits said second band through said first member.

3. The apparatus of claim 2 wherein said second member is positioned to receive said second band from said first member, said second member reflecting said third band from said second member toward said first member.

4. The apparatus of claim 3 wherein said first member receives said third band from said second member and transmits said third band through said first member.

5. The apparatus of claim 4 wherein said first intensity is associated with said first band when first band is being detected by said first detector, and wherein said second intensity is associated with said third band when said third band is being detected by said second detector.

6. The apparatus of claim 5 wherein said second member is a single component selected from the group of components consisting of a mirror, an edge filter, a shortpass filter, a longpass filter, a notch filter, a band reflection filter and a dichroic filter.

7. The apparatus of claim 6 wherein second member is a mirror and said second and third bands have substantially identical wavelengths.

8. The apparatus of claim 7 wherein said first member is a first notch filter.

9. The apparatus of claim 1 wherein said first member is a first notch filter.

10. The apparatus of claim 9 further comprising an entry mirror, the apparatus being operable to permit said notch filter and said second member to rotate in a first direction and said entry mirror to rotate in a second direction opposite said first direction.

11. The apparatus of claim 1 wherein said second member comprises one or more components selected from the group of components consisting of a mirror, an edge filter, a shortpass filter, a longpass filter, a notch filter, a band reflection filter and a dichroic filter.

12. A method of producing multi-spectral balanced images, the method comprising:

(a) producing from incident light by a first member a first band having first band wavelengths and a second band;

(b) producing from said second band by a second member a third band having wavelengths shorter than said first band wavelengths, excluding said first band wavelengths and having wavelengths longer than said first band wavelengths, such that a first intensity associated with said first band is substantially equal to a second intensity associated with said third band when said incident light is uniform;

(c) producing a first image by detecting said first band by a first detector; and

(d) producing a second image by detecting said third band by a second detector after said third band has propagated from said second member to said second detector.

13. The method of claim 12 wherein producing from incident light by a first member a first band having first band wavelengths and a second band comprises receiving said incident light by said first member, reflecting said first band from said first member, and transmitting said second band through said first member.

14. The method of claim 13 wherein producing from said second band by a second member a third band having wavelengths shorter than said first band wavelengths, excluding said first band wavelengths and having wavelengths longer than said first band wavelengths comprises receiving by said second member said second band from said first member and reflecting said third band from said second member toward said first member.

15. The method of claim 14 wherein producing from said second band by a second member a third band having wavelengths shorter than said first band wavelengths, excluding said first band wavelengths and having wavelengths longer than said first band wavelengths comprises transmitting said third band through said first member after receiving by said first member said third band from said second member.

16. The method of claim 15 wherein producing a first image by detecting said first band by a first detector comprises detecting said first intensity, and wherein producing a second image by detecting said third band by a second detector after said third band has propagated from said second member to said second detector comprises detecting said second intensity.

17. The method of claim 16 wherein producing from said second band by a second member a third band having wavelengths shorter than said first band wavelengths, excluding said first band wavelengths and having wavelengths longer than said first band wavelengths comprises producing said third band by a single component selected from the group of components consisting of a mirror, an edge filter, a shortpass filter, a longpass filter, a notch filter, a band reflection filter and a dichroic filter.

18. The method of claim 17 wherein producing from incident light by a first member a first band having first band wavelengths and a second band comprises producing said first and second bands by a first notch filter, and wherein producing said third band by a single component selected from the group of components consisting of a mirror, an edge filter, a shortpass filter, a longpass filter, a notch filter, a band reflection filter and a dichroic filter comprises producing said third band by a mirror such that said second and third bands have substantially identical wavelengths.

19. The method of claim 12 further comprising determining from said first and second images a flow rate associated with a gas plume.

20. An apparatus for multi-spectral balanced imaging, the apparatus comprising:

(a) first means for producing from incident light a first band having first band wavelengths and a second band;

(b) second means for producing from said second band a third band having wavelengths shorter than said first band wavelengths, excluding said first band wavelengths and having wavelengths longer than said first band wavelengths;

(c) first detection means for producing a first image by detecting said first band; and

(d) second detection means for producing a second image by detecting said third band after said third band has propagated from said second means to said second detection means,

wherein a first intensity associated with said first band is substantially equal to a second intensity associated with said third band when said incident light is uniform.