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US4894544A Expired / Lapsed US ⏱️ 0.0 years remaining

Arrays of infrared detector elements

Assignee: BAE Systems Electronics Ltd
•
Filing: 1988-06-14
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Granted: 1990-01-16
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Expires: 2008-06-14
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Abstract

Abstract Each element of an array of infrared detector elements comprises a capacitor formed by a body (11) of pyroelectric or ferroelectric material between a front electrode (14) and a back electrode (12). The elements have individual electrical connections (13) to their back electrode (12) from which there are derived electrical signals which differ as the temperature of the body (11) changes in response to incident infrared radiation (50). These individual electrical connections (13) are provided by a pattern of conductors (13) carried by a support (10) on which the elements are mounted. Each element has at least an infrared-collection area (21) of larger lateral dimensions (x) than at least the electrical connection (13) to the back electrode (12) whereby a peripheral part (23) of each element overhangs and is separated vertically from an underlying part of the support (10). In accordance with the invention, the elements are arranged in a 2-dimensional array with inner elements of the array surrounded by outer elements of the array. The conductors (13 ) to the inner elements extend on a part of the support (10) between the outer elements and below the overhanging peripheral parts (23) of these outer elements. These conductors (13) of the inner elements are separated from the back electrode (12) and overhanging peripheral parts (23) of the outer elements and from the individual electrical connections (13) of these outer elements by a gap (y,z) sufficient to avoid any troublesome parasitic capacitance across a detector element or any significant capacitive cross-talk between the detector elements. The width of the intermediate conductor tracks (13) and the dimensions (y,z) of the surrounding gap may be larger than the spacing between the overhanging peripheral parts (23) of adjacent elements and, for example, as large as or larger than the thickness of the element bodies (11). The array can be fabricated cheaply and reliably using thick-film techniques to form the conductors (13) on a good thermally insulative support (10), so also providing low thermal cross-talk between the detector elements.

Inventors

  • 👤 Andrew A. Turnbull

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 12:24
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/10; G01J5/34; H; H10; H10N; H10N15/00; H10N15/10

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 205 words
An array of infrared detector elements mounted on a support, each element comprising a capacitor formed by a body of pyroelectric or ferroelectric material between a front electrode and a back electrode at respective front and back major faces of the body, which back major face faces the support, the elements having individual electrical connections to their back electrode from which there are derived electrical signals which differ as the temperature of the body changes in response to incident infrared radiation, which individual electrical connections are provided by a pattern of conductors carried by the support, each element having at least an infrared-collection area of larger lateral dimensions than the portion of the electrical connection to the back electrode which underlies the back electrode whereby a peripheral part of each element overhangs and is separated vertically from an underlying part of the support, characterised in that the elements are arranged in a 2-dimensional array with inner elements of the array surrounded by outer elements of the array, and in that the conductors which provide said individual electrical connections to the inner detector elements extend on a part of the support between the outer detector elements and below the overhanging peripheral parts of these outer elements.
Claim 2
Dependent Claim 205 words
An array of infrared detector elements mounted on a support, each element comprising a capacitor formed by a body of pyroelectric or ferroelectric material between a front electrode and a back electrode at respective front and back major faces of the body, which back major face faces the support, the elements having individual electrical connections to their back electrode from which there are derived electrical signals which differ as the temperature of the body changes in response to incident infrared radiation, which individual electrical connections are provided by a pattern of conductors carried by the support, each element having at least an infrared-collection area of larger lateral dimensions than the portion of the electrical connection to the back electrode which underlies the back electrode whereby a peripheral part of each element overhangs and is separated vertically from an underlying part of the support, characterised in that the elements are arranged in a 2-dimensional array with inner elements of the array surrounded by outer elements of the array, and in that the conductors which provide said individual electrical connections to the inner detector elements extend on a part of the support between the outer detector elements and below the overhanging peripheral parts of these outer elements.
Claim 3
Dependent Claim 53 words
An array as claimed in claim 1, further characterised in that the conductors of the inner elements are separated from the back electrode of the outer elements and from the individual electrical connections of these outer elements by a gap larger than a spacing between the peripheral parts of adjacent outer detector elements.
Claim 4
Dependent Claim 44 words
An array as claimed in claim 1, further characterised in that the conductors of the inner elements at least where they extend between the outer elements have a width which is larger than a spacing between the peripheral parts of adjacent outer detector elements.
Claim 5
Dependent Claim 52 words
An array as claimed in claim 1, further characterised in that each detector element comprises an individual body of the pyroelectric or ferroelectric material located beneath the infrared-collection area of that element, and that the lateral dimensions of each individual body is less than those of the infrared-collection area of that element.
Claim 6
Dependent Claim 55 words
An array as claimed in claim 4, further characterised in that each infrared-collection area is formed by a region of infrared-absorbing material which is thermally coupled to the front major face of the underlying body of the detector element so as to transmit heat generated on absorption of the incident infrared radiation to the body.
Claim 7
Dependent Claim 56 words
An array as claimed in claim 5, further characterised in that the individual bodies of the detector elements are mounted between said support and a film of electrically and thermally insulating material, and that the film carries the regions of infrared-absorbing material and one or more common electrical connections to the front electrode of the bodies.
Claim 8
Dependent Claim 45 words
An array as claimed in claim 1, further characterised in that each detector element comprises an individual body of the pyroelectric or ferroelectric material, and that said support comprises a film of electrically and thermally insulating material on which the individual bodies are resiliently supported.
Claim 9
Dependent Claim 36 words
An array as claimed in claim 1, further characterised in that each detector element comprises an individual body of the pyroelectric or ferroelectric material having lateral dimensions corresponding substantially to those of the respective infrared-collection area.
Claim 10
Dependent Claim 51 words
An array as claimed in claim 4, further characterised in that each body is mounted on an elevated conductive part of the pattern of conductors, which elevated conductive part is at a higher level than the level of the conductors on the part of the support between the outer detector elements.
Claim 11
Dependent Claim 24 words
An array as claimed in claim 9, further characterised in that the elevated conductive part is a thickened part of the pattern of conductors.
Claim 12
Dependent Claim 54 words
An array as claimed in claim 9, further characterised in that a recess is present in the part of the support between the outer detector elements, and that the conductors on this part extend on the bottom of the recess so as to be located at a lower level than the elevated conductive parts.
Claim 13
Dependent Claim 27 words
An array as claimed in claim 9, further characterised in that the elevated conductive part has a smaller width than the back electrode of the associated body.

References Cited (Backward Citations)

GB1525562A Cited
US4072863A Cited
GB2030023A Cited
GB2080614A Cited
GB2100058A Cited
JPS5935118A Cited
US4532424A Cited
EP0173368A2 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-01-15 1993-07-17 1994-01-16 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-01-15 1997-07-17 1998-01-16 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-01-15 2001-07-17 2002-01-16 $7700.00 Window Closed / Lapsed

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