US4139291A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System and method for obtaining wide screen Schlieren photographs
Assignee: National Aeronautics and Space Administration
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Filing: 1978-02-09
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Granted: 1979-02-13
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Expires: 1998-02-09
Abstract
Abstract A system for use in Schlieren photography including a large grating, a viewing screen adjacently related to the large grating, a small grating disposed in spaced relation with the large grating, a transparent retainer for confining a transparent medium between the gratings, and optics for imaging the small grating on the large grating including a light source and optically aligned lens for projecting a beam of light along axes extending through the small grating and striking the large grating, subsequent to passing through the medium for thus forming on the screen a Schlieren image of striations resulting from distortions of light rays produced by the medium, and a camera for photographing the Schlieren image projected on the large screen.
Inventors
- 👤 with respect to an invention of Frosch Robert A. Administrator of the National Aeronautics and Space Administration
- 👤 Shakkottai P. Parthasarathy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 05:16
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/50
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
112 words
In a system for obtaining wide screen Schlieren photographs, the improvement comprising: A. means defining a small grating including a plurality of bars arranged in coplanar parallelism; B. a large grating; C. means for imaging said small grating on said large grating including a source of light and a condensing lens for projecting a beam of light along an optic axis extended through said small grating, and projection lens aligned along said axis in spaced relation with the small grating for projecting a magnified image of said small grating on said large grating; and D. a viewing screen adjacently related to said large grating, whereby striae produced in the medium is imaged.
Claim 2
Dependent Claim
112 words
In a system for obtaining wide screen Schlieren photographs, the improvement comprising: A. means defining a small grating including a plurality of bars arranged in coplanar parallelism; B. a large grating; C. means for imaging said small grating on said large grating including a source of light and a condensing lens for projecting a beam of light along an optic axis extended through said small grating, and projection lens aligned along said axis in spaced relation with the small grating for projecting a magnified image of said small grating on said large grating; and D. a viewing screen adjacently related to said large grating, whereby striae produced in the medium is imaged.
Claim 3
Dependent Claim
22 words
The improvement of claim 1 further comprising means for positioning material to be examined between said projection lens and said large grating.
Claim 4
Dependent Claim
15 words
The improvement of claim 1 further comprising means for photographing images projected on said screen.
Claim 5
Dependent Claim
13 words
The improvement of claim 3 wherein the viewing screen comprises a Fresnel lens.
Claim 6
Dependent Claim
25 words
The improvement of claim 4 further comprising camera means disposed in axially spaced relation with said viewing screen for photographing images projected on said screen.
Claim 7
Dependent Claim
14 words
The improvement of claim 3 wherein said viewing screen comprises a light reflective surface.
Claim 8
Dependent Claim
31 words
The improvement of claim 6 wherein said means for photographing images projected on said screen includes a camera having an optic axis angularly related to the plane of said reflective surface.
Claim 9
Independent Claim
76 words
A method for obtaining wide screen Schlieren photographs, the steps comprising: A. directing a beam of light along a path extended from a source through a small grating to a projection lens and thence to a large grating for thus projecting a magnified image of the small grating on the large grating; B. positioning material to be examined between said projection lens and said large grating; and C. photographing the image projected on said large grating.
Claim 10
Independent Claim
76 words
A method for obtaining wide screen Schlieren photographs, the steps comprising: A. directing a beam of light along a path extended from a source through a small grating to a projection lens and thence to a large grating for thus projecting a magnified image of the small grating on the large grating; B. positioning material to be examined between said projection lens and said large grating; and C. photographing the image projected on said large grating.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-02-12 | 1982-08-14 | 1983-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-12 | 1986-08-14 | 1987-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-12 | 1990-08-14 | 1991-02-13 | $7700.00 | Window Closed / Lapsed |