US3775620A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radiation source simulation means
Assignee: McDonnell Douglas Corp
•
Filing: 1972-08-24
•
Granted: 1973-11-27
•
Expires: 1992-08-24
Abstract
Abstract Advanced sensor evaluation and test apparatus comprises a vacuum chamber with an inner cryoshroud, housing an on-axis optical parabolic collimator, a radiant energy source assembly having an output aperture located in the focal plane of the collimator, a calibration monitor consisting of a Cassegrainian type radiometer that occupies one portion of the collimated radiant energy beam and which forms an image of the source on a bolometer, and a pair of scanning mirrors directing energy from another portion of the collimated beam into the entrance aperture of the optical sensor under test. In addition, a background radiant energy generator can direct radiant energy simulating elevated radiation background to the sensor under test which, in turn, forms an enlarged image of the background source in its own detector plane. One version of the source assembly includes at least one blackbody radiation source of variable aperture and temperature with a chopper operating to provide modulated radiation which is projected into an integrating sphere coupled with a source projector. An adjustable dual reflector with one specularly and one diffusely reflecting surface is mounted inside the integrating sphere and can be rotated to predetermined orientations to function in either a specularly reflecting mode or diffusely reflecting mode. In a third mode of operation, the mirror is rotated into an inactive orientation in which it does not intercept the beam entering the integrating sphere. This is the integrating sphere mode of operation. Another version of the source assembly includes at least one blackbody radiation source providing radiation to an integrating sphere coupled with a radiation guide (pipe). The radiation guide can be either a single or dual guide (pipe) and is cooperatively structured to operate with selected transmission patterns (transparent portions) on a movable disc sector positioned at the end of the guide.
Inventors
- 👤 R Meier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:59
CPC Classifications
G; G01; G01J; G01J1/00; G01J1/02; G01J1/08; G01J1/04; G01J1/0407; G01J1/0414; G01J1/0455; G01J5/00; G01J5/52; G01J5/53
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
176 words
For use in exoatmospheric environmental test apparatus including a vacuum chamber for providing and maintaining a predetermined vacuum condition therein, a cryoshroud within said vacuum chamber for providing and maintaining a predetermined temperature therein, an optical collimator contained in said cryoshroud, and a pair of scanning mirrors, a radiant energy source assembly comprising: a source of radiant energy; an integrating sphere including an entrance aperture and an exit aperture, and an adjustable reflecting element mounted therein, said element having a specularly reflecting surface and a diffusely reflecting surface; means for directing the radiant energy from said source into said sphere through said sphere entrance aperture; means for adjusting said element selectively to one of its orientations for specularly reflecting, diffusely reflecting, and integrating sphere operations; and a source projector including an entrance aperture and an exit aperture, said projector entrance aperture being coupled to said sphere exit aperture and said projector exit aperture being positioned at an input opening of said collimator whereby radiant energy from said sphere is directed by said projector into said collimator.
Claim 2
Dependent Claim
176 words
For use in exoatmospheric environmental test apparatus including a vacuum chamber for providing and maintaining a predetermined vacuum condition therein, a cryoshroud within said vacuum chamber for providing and maintaining a predetermined temperature therein, an optical collimator contained in said cryoshroud, and a pair of scanning mirrors, a radiant energy source assembly comprising: a source of radiant energy; an integrating sphere including an entrance aperture and an exit aperture, and an adjustable reflecting element mounted therein, said element having a specularly reflecting surface and a diffusely reflecting surface; means for directing the radiant energy from said source into said sphere through said sphere entrance aperture; means for adjusting said element selectively to one of its orientations for specularly reflecting, diffusely reflecting, and integrating sphere operations; and a source projector including an entrance aperture and an exit aperture, said projector entrance aperture being coupled to said sphere exit aperture and said projector exit aperture being positioned at an input opening of said collimator whereby radiant energy from said sphere is directed by said projector into said collimator.
Claim 3
Dependent Claim
120 words
The invention as defined in claim 1 wherein said element includes a two-faced plano mirror rotatably mounted in said sphere and having a specularly reflecting surface on one side and a diffusely reflecting surface on an opposite side, said two-faced plano mirror being selectively adjustable to one of its orientations for specularly reflecting the radiant energy directed into said sphere onto its exit aperture, diffusely reflecting the radiant energy directed into said sphere onto its exit aperture, and integrating sphere operation in which the radiant energy directed into said sphere is unobstructed by said two-faced mirror in reaching an internal wall surface of said sphere and the diffusely reflecting surface of said two-faced mirror generally faces said sphere exit aperture.
Claim 4
Dependent Claim
58 words
The invention as defined in claim 1 wherein said means for directing the radiant energy from said source into said sphere includes optical means for focusing the radiant energy from said source into said sphere and onto its exit aperture after reflection by said element adjusted to one of its orientations or specularly reflecting and diffusely reflecting operations.
Claim 5
Dependent Claim
156 words
The invention as defined in claim 1 wherein said projector includes a housing having said projector entrance aperture therein, a projector concave spherical mirror having a central aperture aligned with and positioned a predetermined distance before said projector entrance aperture, and a folding plano mirror having a central aperture aligned with and positioned a predetermined distance before said projector converging mirror central aperture, said folding plano mirror central aperture being located at the focal plane of said collimator wHereby radiant energy from said sphere enters said projector entrance aperture, passes through the central aperture of said projector concave spherical mirror, is reflected by said folding plano mirror to said projector concave spherical mirror which reflects the radiant energy back through said folding plano mirror central aperture and into said collimator, a reduced image of said sphere exit aperture which coincides with said projector input aperture being formed in the central aperture of said folding plano mirror.
Claim 6
Dependent Claim
21 words
The invention as defined in claim 1 further comprising means for varying the amount of radiant energy directed into said sphere.
Claim 7
Dependent Claim
27 words
The invention as defined in claim 1 further comprising a chopper means positioned before said source for modulating the radiant energy emitted therefrom at a predetermined frequency.
Claim 8
Dependent Claim
68 words
The invention as defined in claim 2 wherein said means for directing the radiant energy from said source into said sphere includes a converging mirror for focusing the radiant energy from said source into said sphere, said converging mirror having a focal plane placed at said projector input aperture after reflection by said adjusted element adjusted to one of its orientations for specularly reflecting and diffusely reflecting operations.
Claim 9
Dependent Claim
25 words
The invention as defined in claim 4 further comprising variable aperture means mounted in said housing for varying the size of said projector input aperture.
Claim 10
Dependent Claim
33 words
The invention as defined in claim 5 wherein said varying means includes an attenuator adjustable to attenuate a selected beam portion of the radiant energy from said source being directed into said sphere.
Claim 11
Dependent Claim
37 words
The invention as defined in claim 1 further comprising a sensor under test in said apparatus, and a variable background radiation generator for providing background irradiance broadly superimposed in the detection plane of said sensor under test.
Claim 12
Dependent Claim
119 words
The invention as defined in claim 10 wherein said sensor includes a telescope and a detector located at the focal plane of said telescope, and said background generator includes a radiation source of variable temperature and predetermined size aperture, a filter wheel having a plurality of spectral and spatially structured filters which can be selectively positioned before said background source aperture, and a Cassegrainian type collimator assembly of short focal length for directing the background radiant energy parallel to the optical axis of said sensor telescope and into a peripheral portion of the entrance aperture thereof whereby an enlarged image of said background source aperture is broadly superimposed on said detector located at the focal plane of said telescope.
Claim 13
Dependent Claim
50 words
The invention as defined in claim 11 wherein said background generator further includes means for rotating said filter wheel selectively either in steps or continuously whereby said background radiant energy can be varied in a predetermined manner according to the type and sequence of filters mounted in said filter wheel.
Claim 14
Dependent Claim
65 words
The invention as defined in claim 3 further comprising means for collimating the radiant energy from said source, and an adjustable reflecting structure including at least a specularly reflecting surface and a diffracting reflection surface, said structure being selectively adjustable to one of its orientations for specularly reflecting and diffracting reflection operations to reflect the radiant energy from said source to said optical focusing means.
Claim 15
Dependent Claim
64 words
The invention as defined in claim 7 further comprising means for collimating the radiant energy from said source, and an adjustable reflecting structure including at least a specularly reflecting surface and a diffracting reflection surface, said structure being selectively adjustable to one of its orientations for specularly reflecting and diffracting reflection operations to reflect the radiant energy from said source to said converging mirror.
Claim 16
Dependent Claim
43 words
The invention as defined in claim 13 wherein said structure includes A polyhedron having a plurality of specularly reflecting and diffracting reflection surfaces, said structure being rotatably mounted and selectively adjustable to one of its orientations for specularly reflecting and diffracting reflection operations.
Claim 17
Dependent Claim
92 words
In a radiant energy source assembly, an integrating sphere structure comprising: a hollow sphere including at least one entrance aperture and an exit aperture, said sphere having a diffusely reflecting internal wall surface; and an adjustable reflecting element mounted in said sphere, said element being selectively adjustable to one of an obstructing position for reflecting radiant energy entering said entrance aperture out of said exit aperture and an unobstructing position for allowing the entering radiant energy to impinge upon said internal surface to provide diffused radiant energy out of said exit aperture.
Claim 18
Dependent Claim
92 words
In a radiant energy source assembly, an integrating sphere structure comprising: a hollow sphere including at least one entrance aperture and an exit aperture, said sphere having a diffusely reflecting internal wall surface; and an adjustable reflecting element mounted in said sphere, said element being selectively adjustable to one of an obstructing position for reflecting radiant energy entering said entrance aperture out of said exit aperture and an unobstructing position for allowing the entering radiant energy to impinge upon said internal surface to provide diffused radiant energy out of said exit aperture.
Claim 19
Dependent Claim
38 words
The invention as defined in claim 16 wherein said element includes a two-faced plano mirror rotatably mounted in said sphere and having a specularly reflecting surface on one face and a diffusely reflecting surface on the opposite face.
Claim 20
Dependent Claim
49 words
The invention as defined in claim 16 wherein said sphere has a compound diffusely reflecting internal wall surface, said internal wall surface including a convex diffused wall surface portion located approximately opposite diametrically to said entrance aperture for diffusely reflecting the incoming radiant energy generally towards said exit aperture.
References Cited (Backward Citations)
US3222522A
Cited
US3563658A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |