US4317063A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pyroelectric detectors
Assignee: GEC-MARONI Ltd
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Filing: 1979-10-25
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Granted: 1982-02-23
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Expires: 1999-10-25
Abstract
Abstract A reticulated pyroelectric target, for the detection of infra red radiation, comprising a plurality of closely packed islands of pyroelectric material separated by a plurality of relatively narrow grooves in which in order to physically strengthen the target the islands and grooves are so shaped that the grooves do not form a straight line over any appreciable portion of the target surface. Preferably the islands are hexagonal to provide a good packing density.
Inventors
- 👤 David J. Pedder
- 👤 David J. Warner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:32
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/36; H01J29/39; H01J29/45; H01J29/458
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
120 words
A reticulated pyroelectric target for the detection of thermal radiation and having a target surface, and comprising a plurality of islands of pyroelectric material disposed on said target surface and separated by a plurality of grooves, each said groove adjacent each said island forming a portion of a boundary of each said island, each said groove being limited in length to and coinciding with said portion of said boundary of each said island, and wherein each groove in respect to any one said island forms, at its junction with adjacent grooves of adjacent said islands, all non-straight lines with the adjacent grooves of adjacent said islands, whereby to minimize lines of weakness and improve structural strength over the target surface.
Claim 2
Dependent Claim
120 words
A reticulated pyroelectric target for the detection of thermal radiation and having a target surface, and comprising a plurality of islands of pyroelectric material disposed on said target surface and separated by a plurality of grooves, each said groove adjacent each said island forming a portion of a boundary of each said island, each said groove being limited in length to and coinciding with said portion of said boundary of each said island, and wherein each groove in respect to any one said island forms, at its junction with adjacent grooves of adjacent said islands, all non-straight lines with the adjacent grooves of adjacent said islands, whereby to minimize lines of weakness and improve structural strength over the target surface.
Claim 3
Dependent Claim
28 words
A reticulated pyroelectric target as claimed in claim 1, wherein each island is hexagonal in shape, and wherein the plurality of islands forms a close packed hexagonal array.
Claim 4
Dependent Claim
20 words
A reticulated pyroelectric target as claimed in claim 2, wherein the hexagonal islands are formed with internal angles of 120°.
Claim 5
Dependent Claim
22 words
A reticulated pyroelectric target as claimed in claim 2, wherein the hexagonal islands are formed with internal angles of 135° and 90°.
Claim 6
Dependent Claim
54 words
A reticulated pyroelectric target as claimed in claim 1, wherein the target comprises a structure having a pitch, said target detecting infra-red radiation having a wavelength, and wherein the grooves have a width which is less than 1/4 the pitch of the structure and less than the wavelength of the infra-red radiation being detected.
Claim 7
Dependent Claim
29 words
A reticulated pyroelectric target as claimed in claim 1, wherein the grooves separating the islands are inclined at an acute angle with respect to the plane of the target.
Claim 8
Dependent Claim
94 words
A reticulated pyroelectric target as claimed in claim 1, wherein the target is produced using a holder for retaining the target substantially flat during reticulation of the target, said holder comprising a plurality of fingers, and at least one annular support means for supporting said plurality of fingers, said plurality of fingers projecting inwardly from said at least one annular support means, said at least one annular support means being provided with a central aperture such that said at least one annular support means does not cover the whole of the target during reticulation.
Claim 9
Dependent Claim
31 words
A reticulated pyroelectric target as claimed in claim 7, wherein the reticulations extend to the extreme edges of the disc so as to relieve the stresses produced during the reticulation process.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-02-22 | 1985-08-24 | 1986-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-02-22 | 1989-08-24 | 1990-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-02-22 | 1993-08-24 | 1994-02-23 | $7700.00 | Window Closed / Lapsed |