US3765772A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Interferometric angular sensor and reference
Assignee: United States Department of the Army
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Filing: 1972-06-30
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Granted: 1973-10-16
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Expires: 1992-06-30
Abstract
Abstract An interferometric angular movement sensor which maintains a stable alignment of a surface with respect to a reference plane. The sensor relies upon the formation of non-localized circular fringes formed in reflection from two reflective surfaces, one of which is positioned in the reference plane and the other of which is mounted on the surface sought to be maintained in angular relationship with said reference plane. The fringes are formed as a result of directing divergent light from a source onto the two reflective surfaces. The position of the fringes on an appropriately located screen detector will indicate whether any misalignment has occurred, and by connecting said detector to appropriate servo-mechanisms, realignment of the two surfaces can be easily maintained to a degree of accuracy heretofore unobtainable.
Inventors
- 👤 C Willett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 00:51
CPC Classifications
G; G01; G01B; G01B9/00; G01B9/02; G01B9/02015; G01B9/02017; G01B9/02021; G01B11/00; G01B11/26; G01B9/02027; G01B9/02055; G01B9/02056; G01B9/02057
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
138 words
An interferometric angular movement sensor for detecting the angular displacement of a surface with respect to a reference plane, comprising: a. a first reflective coating positioned in said reference plane; b. a second reflective coating which forms a side of the surface sought to be maintained in stable relationship to said reference plane; c. means for projecting divergent light onto said first and second reflective coatings such that non-localized circular interference fringes are formed as a result of interference between light reflected at said first coating and light that has been refracted at said first coating and reflected at said second coating; and d. means for detecting said non-localized conical interference fringes and for translating the position of said fringes on said detecting means into commands for reducing the angular misalignment between said first and second reflective coatings.
Claim 2
Dependent Claim
138 words
An interferometric angular movement sensor for detecting the angular displacement of a surface with respect to a reference plane, comprising: a. a first reflective coating positioned in said reference plane; b. a second reflective coating which forms a side of the surface sought to be maintained in stable relationship to said reference plane; c. means for projecting divergent light onto said first and second reflective coatings such that non-localized circular interference fringes are formed as a result of interference between light reflected at said first coating and light that has been refracted at said first coating and reflected at said second coating; and d. means for detecting said non-localized conical interference fringes and for translating the position of said fringes on said detecting means into commands for reducing the angular misalignment between said first and second reflective coatings.
Claim 3
Dependent Claim
33 words
The invention according to claim 1 wherein said first reflective coating is mounted on a glass plate located in said reference plane such that said first reflective coating faces said second reflective coating.
Claim 4
Dependent Claim
46 words
The invention according to claim 2 wherein said detecting means comprises a quadrant detector divided into at least four sectors, each of said sectors comprising a detection screen and means for transmitting the signals detected thereon to means for realigning said surface with said reference plane.
Claim 5
Dependent Claim
37 words
The invention according to claim 3 further comprising a plurality of said sensors each having a pair of reflective coatings and its own light source such that the angular movement of a multifaceted object can be monitored.
Claim 6
Independent Claim
66 words
A device for detecting angular displacement of a surface with respect to a reference plane comprising: a. a first partially reflective coating positioned in said reference plane; b. a second reflective coating positioned on said surface and parallel to said reference plane; c. means for projecting divergent light through said first coating and onto said second coating; and d. means for detecting non-localized conical interference fringes.
Claim 7
Independent Claim
66 words
A device for detecting angular displacement of a surface with respect to a reference plane comprising: a. a first partially reflective coating positioned in said reference plane; b. a second reflective coating positioned on said surface and parallel to said reference plane; c. means for projecting divergent light through said first coating and onto said second coating; and d. means for detecting non-localized conical interference fringes.
Claim 8
Dependent Claim
14 words
The device of claim 5 wherein said first and second coatings face each other.
Claim 9
Dependent Claim
21 words
The device of claim 6 wherein said means for detecting comprises a planar light detector positioned parallel to said first coating.
Claim 10
Dependent Claim
27 words
The device of claim 7 wherein said means for projecting divergent light comprises means for transmitting light through an aperture in the center of said detecting means.
Claim 11
Dependent Claim
19 words
The device of claim 7 wherein said light detectOr comprises a quadrant detector divided into at least four sectors.
Claim 12
Dependent Claim
22 words
The device of claim 7 further comprising means responsive to detected light for realigning said surface with respect to said reference plane.
References Cited (Backward Citations)
US3224323A
Cited
US3470377A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-15 | 1977-04-16 | 1977-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-15 | 1981-04-16 | 1981-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-15 | 1985-04-16 | 1985-10-16 | $7700.00 | Window Closed / Lapsed |