US3819940A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical instruments
Assignee: Hawker Siddeley Dynamics Ltd
•
Filing: 1973-06-07
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Granted: 1974-06-25
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Expires: 1993-06-07
Abstract
Abstract An optical instrument wherein an optical signal is projected on to a sensor array or sensitive medium and angular deflections of the path of the optical signal about an instrument signal source as centre appear as displacements from a datum lying in the general plane of the sensor array or sensitive medium, the instrument having an optical axis passing through said source and normal to said plane, characterized in that, to correct for the tangent law error that would otherwise arise, a correcting optical device is interposed in the signal path and has its surface receiving the signal curved, in the concave sense, about a centre lying on or intersecting the optical axis of the instrument, the curvature being of radius R, where R is greater than the distance t from said instrument signal source to the point in said curved surface that lies on said optical axis, the surface of the correcting optical device facing the sensor array being plane.
Inventors
- 👤 A Laws
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:37
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/04; G02B6/06; G02B6/08; G01; G01J; G01J1/00; G01J1/02; G01J1/04; G01J1/0407; G01J1/0411; G01J1/0425; G01J1/42; G01J1/4228; G01S; G01S3/00; G01S3/78; G01S3/781; G01J1/0204; G01J1/0209
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
161 words
An optical instrument wherein an optical signal is projected on to a sensor array or sensitive medium and angular deflections of the path of the optical signal about an instrument signal source as centre appear as displacements from a datum lying in the general plane of the sensor array or sensitive medium the instrument having an optical axis passing through said source and normal to said plane, characterised in that, to correct for the tangent law error that would otherwise arise, a correcting optical device is interposed in the signal path and has its surface receiving the signal curved, in the concave sense, about a centre lying on or intersecting the optical axis of the instrument, the curvature being of radius R, where R is greater than the distance t from said instrument signal source to the point in said curved surface that lies on said optical axis, the surface of the correcting optical device facing the sensor array being plane.
Claim 2
Dependent Claim
161 words
An optical instrument wherein an optical signal is projected on to a sensor array or sensitive medium and angular deflections of the path of the optical signal about an instrument signal source as centre appear as displacements from a datum lying in the general plane of the sensor array or sensitive medium the instrument having an optical axis passing through said source and normal to said plane, characterised in that, to correct for the tangent law error that would otherwise arise, a correcting optical device is interposed in the signal path and has its surface receiving the signal curved, in the concave sense, about a centre lying on or intersecting the optical axis of the instrument, the curvature being of radius R, where R is greater than the distance t from said instrument signal source to the point in said curved surface that lies on said optical axis, the surface of the correcting optical device facing the sensor array being plane.
Claim 3
Dependent Claim
35 words
An instrument according to claim 1, wherein the correcting optical device comprises a multiplicity of fibre optical elements all arranged parallel to the optical axis and normal to said plane surface and of varying lengths.
Claim 4
Dependent Claim
60 words
An instrument according to claim 1 wherein the instrument signal source is a slit or a series of parallel slits or a shading edge, upon which falls light from source external to the instrument, and the curved surface of the correcting optical device is a part-cylindrical surface generated about an axis parallel to the slit or slits or shading edge.
Claim 5
Dependent Claim
32 words
An instrument according to claim 1, wherein the instrument signal source is a point source, e.g. a ''''pin-hole'''' aperture, and the curved surface of the correcting optical element is a part-spherical surface.
Claim 6
Dependent Claim
31 words
An instrument according to claim 1 wherein a refractory body is interposed between the instrument signal source and the correcting optical device, being contiguous with the curved surface of said device.
Claim 7
Dependent Claim
26 words
An instrument according to claim 1 wherein the plane surface of the correcting optical device is spaced from the sensor array and a lens is interposed.
Claim 8
Dependent Claim
16 words
An instrument according to claim 1 wherein the sensor array comprises a multiplicity of photo-diode cells.
Claim 9
Dependent Claim
42 words
An instrument according to claim 1 having a number of angularly-displaced optical axis mutually intersecting at the instrument signal source, and wherein the sensor array is divided into sections each disposed in a plane at right angles to a respective optical axis.
Claim 10
Dependent Claim
24 words
An instrument according to claim 8, wherein each sensor array has a respective correcting optical device disposed between itself and the instrument signal source.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |