Patent US4840465A successfully refreshed from Google Patents.
US4840465A
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Device for correcting distortion
Assignee: Thomson TRT Defense
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Filing: 1987-11-19
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Granted: 1989-06-20
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Expires: 2007-11-19
Abstract
Abstract Device for correcting the differential distortion resulting from simultaneous observation of a field of view at two distinct locations through a shield transparent in a given spectral band, which shield has a shape generating the distortion when a receiver which is sensitive in the spectral band is arranged at each of the locations. The correction is effected by an optical system arranged between the shield and one or the other receiver and comprising an anamorphic assembly (11, 12) producing an anamorphosis in a first direction associated with an element (13) introducing a curvature in a second direction, while the distortion produced by this system has a direction opposite to the differential distortion.
Inventors
- 👤 Fernand R. Loy
- 👤 Jean-Claude Perrin
- 👤 Joel Rollin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:57
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/64; G02B13/00; G02B13/08; G02B13/10; G02B27/01; G02B27/0101; G02B27/0149; G02B2027/0154
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
101 words
A device correcting the differential distortion resulting from superimposing the images received by first and second receivers sensitive in a given spectral band, said images resulting from simultaneous observation of a field of view at two distinct locations through a shield transparent in said given spectral band, said shield having a shape generating distortion without rotational symmetry, said device comprising an optical correction system having a modular structure using parallel beams and being arranged between said shield and said second receiver, said system introducing a distortion having a curvature and variation of length of lines opposite those of said differential distortion.
Claim 2
Independent Claim
101 words
A device correcting the differential distortion resulting from superimposing the images received by first and second receivers sensitive in a given spectral band, said images resulting from simultaneous observation of a field of view at two distinct locations through a shield transparent in said given spectral band, said shield having a shape generating distortion without rotational symmetry, said device comprising an optical correction system having a modular structure using parallel beams and being arranged between said shield and said second receiver, said system introducing a distortion having a curvature and variation of length of lines opposite those of said differential distortion.
Claim 3
Dependent Claim
66 words
A device as claimed in claim 7, characterized in that the optical correction system has an anamorphic function creating the length variation in a first direction and an aberrating function forming the curvature in a second direction, the angle of the directions being adjustable to any value for simulating any form of distortion and the anamorphic and deflecting functions being realized by means of independent groups.
Claim 4
Dependent Claim
18 words
A device as claimed in claim 2, characterized in that said first and second directions are mutually perpendicular.
Claim 5
Dependent Claim
22 words
A device as claimed in claim 2, characterized in that said first and second directions make an arbitrary angle with each other.
Claim 6
Dependent Claim
48 words
A device as claimed in claim 2, characterized in that the anamorphic function is realized by means of two prisms having the same angle and having the same refractive index and being arranged head-to-tail and in that the aberrating function is realized by means of a single prism.
Claim 7
Dependent Claim
41 words
A device as claimed in claim 5, characterized in that the chromatism introduced by the aberrating prism is corrected by the addition of another prism having a different angle and a different refractive index, said two prisms constituting an achromatic assembly.
References Cited (Backward Citations)
US4245890A
Cited
US4580879A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-19 | 1992-12-19 | 1993-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-19 | 1996-12-19 | 1997-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-19 | 2000-12-19 | 2001-06-20 | $7700.00 | Window Closed / Lapsed |