Patent US4080532A successfully refreshed from Google Patents.
US4080532A
Expired / Lapsed
US
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Ferroelectric imaging system
Assignee: Texas Instruments Inc
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Filing: 1977-05-13
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Granted: 1978-03-21
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Expires: 1997-05-13
Abstract
Abstract A ferroelectric imaging system is taught. The system comprises a lens system, detector matrix, drive and readout electronics, controller, video processor and display. The lens system is a lens system for focusing electromagnetic energy from a scene onto a detector matrix. The drive and readout electronics selectively bias the elements of the detector matrix, and readout voltage signals indicative of the infrared energy impinging on each element of the detector matrix. The controller section includes clocks and shift registers, respectively, for timing the electronic drive and readout electronics, and for selecting in a desired order the matrix elements for readout. The controller also controls the readout signal input to the video processor which processes the voltage signal output of the detector matrix into video signals. The video signals are applied to a display means such as, for example, a cathode ray tube for display. The detector matrix includes a ferroelectric optical transducer which includes a body of ferroelectric material and a plurality of orthogonal leads formed on opposing major surfaces of the ferroelectric material. The detector matrix is mounted upon a heated substrate in a vacuum housing having an appropriate energy transmitting window. The body of ferroelectric material and orthogonal leads form a plurality of thermal sensitive capacitors with the ferroelectric material acting as the dielectric and the orthogonal leads as plates. The plurality of capacitors is divided into two portions; one portion receiving energy to vary their capacitance in proportion to the energy received, and a second portion shielded from the energy to provide reference capacitors. The thermal responsive capacitors and reference capacitors are arranged with the drive and output electronics to form a bridge having an output voltage indicative of the thermal energy detected.
Inventors
- 👤 George S. Hopper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:16
CPC Classifications
H; H04; H04N; H04N25/00; H04N25/70; H04N25/76; H04N23/00; H04N23/20; H04N25/60; H04N25/67; H04N25/671; H04N25/779; H04N25/7795
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
121 words
A thermal imager comprising: (a) a drive circuit means for biasing a matrix of selectively spaced thermal sensitive capacitors; (b) a matrix of selectively spaced thermal sensitive capacitors connected to said drive means for biasing at a preselected potential; (c) means for positioning the matrix of selectively spaced thermal sensitive capacitors in a path of thermal energy emanating from a scene thereof, whereby the capacitance of each capacitor of the matrix of selectively spaced thermal sensitive capacitors is varied according to the intensity of the thermal energy impinging thereon; and (d) a signal processor means for reading out and producing display signals responsively to the varying potentials on the thermal sensitive capacitors of the matrix of selectively spaced thermal sensitive capacitors.
Claim 2
Dependent Claim
121 words
A thermal imager comprising: (a) a drive circuit means for biasing a matrix of selectively spaced thermal sensitive capacitors; (b) a matrix of selectively spaced thermal sensitive capacitors connected to said drive means for biasing at a preselected potential; (c) means for positioning the matrix of selectively spaced thermal sensitive capacitors in a path of thermal energy emanating from a scene thereof, whereby the capacitance of each capacitor of the matrix of selectively spaced thermal sensitive capacitors is varied according to the intensity of the thermal energy impinging thereon; and (d) a signal processor means for reading out and producing display signals responsively to the varying potentials on the thermal sensitive capacitors of the matrix of selectively spaced thermal sensitive capacitors.
Claim 3
Dependent Claim
21 words
A thermal imager according to claim 1 wherein said matrix of selectively spaced thermal sensitive capacitors form an infrared detector matrix.
Claim 4
Dependent Claim
55 words
A thermal imager according to claim 2 wherein said signal processing means includes at least one reference capacitor connected to the drive circuit means and the infrared detector matrix of selectively spaced thermal sensitive capacitors for producing signals equal to the difference of the biasing potential on the thermal sensitive capacitors and the reference capacitor.
Claim 5
Dependent Claim
45 words
A thermal imager according to claim 2 wherein the signal processor means coupled to the infrared detector matrix includes a video processor coupled to the detector matrix for producing video signals, and a display means connected to the video processor for displaying the video signals.
Claim 6
Dependent Claim
31 words
A thermal imager according to claim 1 further including a thermal lens system for focusing the thermal energy emanating from the scene onto the matrix of selectively spaced thermal sensitive capacitors.
Claim 7
Dependent Claim
19 words
A thermal imager according to claim 1 wherein said matrix is an addressable matrix array of thermal sensitive capacitors.
Claim 8
Dependent Claim
65 words
A thermal imager according to claim 1 wherein the matrix of selectively spaced thermal sensitive capacitors includes a body of ferroelectric material sandwiched between a first and second plurality of spaced leads selectively arranged to form the matrix of spaced thermal sensitive capacitors, the body of ferroelectric material and leads forming, respectively, the dielectric and plates of the matrix of selectively spaced thermal sensitive capacitors.
Claim 9
Dependent Claim
61 words
A thermal imager according to claim 1 wherein said matrix of selectively spaced thermal sensitive capacitors includes a shield means for selectively shielding at least one capacitor of the matrix array of thermal sensitive capacitors from thermal energy emanating from the scene, said at least one shielded capacitor forming a reference capacitor for the matrix of selectively spaced thermal sensitive capacitors.
Claim 10
Dependent Claim
33 words
A thermal imager according to claim 7 wherein said dielectric of ferroelectric material includes ferroelectric material having a Curie point between about 0° and 150° centigrade for operation at temperatures near ambient temperature.
Claim 11
Dependent Claim
16 words
A thermal imager according to claim 7 wherein said dielectric of ferroelectric material is barium titanate.
Claim 12
Dependent Claim
175 words
A thermal imager according to claim 2 wherein the said detector matrix of thermal sensitive capacitors includes a first portion of thermal sensitive capacitors exposed to impinging thermal energy and a second portion of thermal sensitive capacitors, and further includes: (a) a shield means for shielding the second portion of thermal sensitive capacitors from thermal energy emanating from the scene; (b) a drive means including a signal source, said signal source coupled to the thermal sensitive capacitors shielded by the shield means to bias them to form a plurality of reference elements, and to a multiplexer, said multiplexer coupled to the first portion of the thermal sensitive capacitors for selectively biasing the first portion of thermal sensitive capacitors, said first portion of biased thermal sensitive capacitors responsive to impinging thermal energy to vary the bias potential; and (c) a readout means, said readout means including a multiplexer, said first and second portions of thermal sensitive capacitors connected to the multiplexer for producing selectively signals representative of the thermal energy impinging on the thermal sensitive capacitors.
Claim 13
Dependent Claim
31 words
A thermal imager according to claim 11 wherein the drive means and readout means includes a clock and gate means for controlling, respectively, the operation of the drive and signal multiplexers.
Claim 14
Dependent Claim
285 words
A ferroelectric imaging system comprising: (a) a thermal lens system for focusing thermal energy emanating from a scene; (b) a matrix of ferroelectric ceramic capacitors, a first portion of said ferroelectric ceramic capacitors in the optical path of the focused thermal energy, a shield, and a second portion of said ferroelectric ceramic capacitors shielded by the shield from the focused thermal energy; (c) a drive means including first and second signal generators and a scan multiplexer, said first and second generators having terminals connected to a common ground, and to said first and second ferroelectric ceramic capacitors to form a bridge whereby the thermal energy impinging on the first portion of the ferroelectric ceramic capacitors changes the dielectric constant thereof in proportion to the intensity of the impinging thermal energy to vary the biasing potential and said bridge provides a difference potential indicative of the thermal energy impinging on the first portion of ferroelectric ceramic capacitors; (d) a readout means including a plurality of preamplifiers coupled to junctions of the first and second portions of the ferroelectric ceramic capacitors, and a signal multiplexer coupled to the plurality of preamplifiers for selectively receiving amplified signals representative of the thermal energy impinging on the first portion of ferroelectric ceramic capacitors; (e) a controller means including clocking and gate means for selectively actuating the scan multiplexer and signal multiplexer, respectively, of the drive and readout means; (f) a video processor coupled to the signal multiplexer and controller for processing the electrical signals indicative of the thermal energy impinging on the first portion of ferroelectric ceramic capacitors into video signals; and (g) a display means connected to the video processor for visually displaying the thermal image of the scene.
Claim 15
Dependent Claim
285 words
A ferroelectric imaging system comprising: (a) a thermal lens system for focusing thermal energy emanating from a scene; (b) a matrix of ferroelectric ceramic capacitors, a first portion of said ferroelectric ceramic capacitors in the optical path of the focused thermal energy, a shield, and a second portion of said ferroelectric ceramic capacitors shielded by the shield from the focused thermal energy; (c) a drive means including first and second signal generators and a scan multiplexer, said first and second generators having terminals connected to a common ground, and to said first and second ferroelectric ceramic capacitors to form a bridge whereby the thermal energy impinging on the first portion of the ferroelectric ceramic capacitors changes the dielectric constant thereof in proportion to the intensity of the impinging thermal energy to vary the biasing potential and said bridge provides a difference potential indicative of the thermal energy impinging on the first portion of ferroelectric ceramic capacitors; (d) a readout means including a plurality of preamplifiers coupled to junctions of the first and second portions of the ferroelectric ceramic capacitors, and a signal multiplexer coupled to the plurality of preamplifiers for selectively receiving amplified signals representative of the thermal energy impinging on the first portion of ferroelectric ceramic capacitors; (e) a controller means including clocking and gate means for selectively actuating the scan multiplexer and signal multiplexer, respectively, of the drive and readout means; (f) a video processor coupled to the signal multiplexer and controller for processing the electrical signals indicative of the thermal energy impinging on the first portion of ferroelectric ceramic capacitors into video signals; and (g) a display means connected to the video processor for visually displaying the thermal image of the scene.
Claim 16
Dependent Claim
26 words
A ferroelectric imaging system according to claim 13 wherein said thermal lens system is an IR lens system for focusing IR energy emanating from a scene.
Claim 17
Dependent Claim
157 words
A ferroelectric imaging system according to claim 13 further including a housing having major opposing sides, an IR window mounted in one of said major opposing sides for admitting IR energy, a substrate mounted in the other of said major opposing sides, the substrate having a well formed therein, a first lead pattern formed on the well side of the substrate, a layer of ferroelectric material forming a dielectric layer in the well over the first lead pattern, a second lead pattern orthogonally positioned as to the first lead pattern over the dielectric layer of ferroelectric material, said first and second orthogonal lead patterns coacting with the dielectric layer of ferroelectric material to form the matrix of ferroelectric ceramic capacitors, and wherein said housing has a portion forming the shield for shielding the second portion of said ferroelectric ceramic capacitors from thermal energy passing through the IR window to the first portion of said ferroelectric ceramic capacitors.
Claim 18
Dependent Claim
95 words
A ferroelectric imaging system according to claim 13 further including a housing having major opposing sides, a window mounted in one of said major opposing sides for admitting light, a substrate mounted in the other of said major opposing sides, said substrate supporting a dielectric of ferroelectric material having opposing major surfaces, and leads formed on the opposing major surfaces of the dielectric, the leads on one major opposing surface being mutually perpendicular to the leads on the other major opposing surface, the leads and dielectric coacting to form the matrix of ferroelectric ceramic capacitors.
Claim 19
Dependent Claim
22 words
A ferroelectric imaging system according to claim 15 further including a heater for maintaining the ferroelectric material substantially at its Curie temperature.
Claim 20
Dependent Claim
24 words
A ferroelectric imaging system according to claim 16 further including a heater for maintaining the dielectric of ferroelectric material at about its Curie temperature.
Claim 21
Independent Claim
173 words
A method of fabricating a thermal imaging system comprising: (a) mounting on a substrate a matrix of thermal sensitive capacitors having dielectrics with Curie temperatures between about 0° C to about 150° C and at least one reference capacitor; (b) mounting the substrate supporting the matrix of thermal sensitive capacitors and at least one reference capacitor within a housing with the matrix of thermal sensitive capacitors in the optical path of the housing for detecting thermal energy emanating from a scene; (c) connecting the matrix of thermal sensitive capacitors and at least one reference capacitor to drive and readout electronics for selectively biasing the thermal sensitive capacitors and at least one reference capacitor, and reading out electrical signals representative of the thermal energy impinging on the matrix of thermal sensitive capacitors; (d) connecting the electrical signals indicative of the thermal image of the scene to a video processor for processing the signals into video signals; and (e) connecting the video signals to a display means for producing a visual display of the scene.
Claim 22
Independent Claim
173 words
A method of fabricating a thermal imaging system comprising: (a) mounting on a substrate a matrix of thermal sensitive capacitors having dielectrics with Curie temperatures between about 0° C to about 150° C and at least one reference capacitor; (b) mounting the substrate supporting the matrix of thermal sensitive capacitors and at least one reference capacitor within a housing with the matrix of thermal sensitive capacitors in the optical path of the housing for detecting thermal energy emanating from a scene; (c) connecting the matrix of thermal sensitive capacitors and at least one reference capacitor to drive and readout electronics for selectively biasing the thermal sensitive capacitors and at least one reference capacitor, and reading out electrical signals representative of the thermal energy impinging on the matrix of thermal sensitive capacitors; (d) connecting the electrical signals indicative of the thermal image of the scene to a video processor for processing the signals into video signals; and (e) connecting the video signals to a display means for producing a visual display of the scene.
Claim 23
Dependent Claim
50 words
A method of fabricating a thermal imaging system according to claim 19 further comprising: attaching to the housing a lens system in the optical path from a scene to the matrix of thermal sensitive capacitors for focusing thermal energy emanating from the scene onto the matrix of thermal sensitive capacitors.
Claim 24
Dependent Claim
38 words
A method of fabricating a thermal imaging system according to claim 20 further comprising mounting a window in the housing between the lens system and the matrix of thermal sensitive capacitors, said window being transmissive of thermal energy.
Claim 25
Dependent Claim
75 words
A method of fabricating a thermal imaging system according to claim 19 wherein said matrix of thermal sensitive capacitors mounted in the substrate comprises forming a dielectric of a ferroelectric ceramic material, and forming spaced leads on opposing major surfaces of the dielectric; said leads on one of the major surfaces in an angular relationship as to the leads on the other major surface whereby the matrix of selectively spaced thermal sensitive capacitors are formed.
Claim 26
Dependent Claim
33 words
A method of fabricating a thermal imaging system according to claim 19 further comprising: heating the substrate to warm the dielectric of the matrix of thermal sensitive capacitors to about its Curie temperature.
Claim 27
Dependent Claim
29 words
A thermal imager according to claim 5 wherein the thermal lens system and matrix of selectively spaced thermal sensitive capacitors are stationary for forming a staring infrared detector system.
Claim 28
Dependent Claim
20 words
A thermal imager according to claim 9 further including a heater for heating the ferroelectric material to its Curie point.
Claim 29
Dependent Claim
16 words
A thermal imager according to claim 7 wherein the body of ferroelectric material is a slab.
Claim 30
Dependent Claim
28 words
A thermal imager according to claim 7 wherein the body of ferroelectric material is a powder having at least one side sintered for supporting a plurality of leads.
Claim 31
Dependent Claim
132 words
A thermal imager comprising: (a) a drive circuit; (b) a two dimensional detector array of ferroelectric thermal detector elements having first and second portions connected to the drive circuit for biasing, each detector element of the first portion responsive to thermal energy of a scene impinging thereon to vary the voltage at its output by an amount representative of the intensity of the impinging thermal energy, and the second portion providing reference output voltages; (c) a comparator means for comparing the outputs of the first and second portions of ferroelectric thermal detector elements of the two dimensional array; and (d) a signal processing means operatively connected to the comparator for producing video signals representative of the scene whereby an image representative of the thermal radiation from the scene is presented for display.
Claim 32
Dependent Claim
132 words
A thermal imager comprising: (a) a drive circuit; (b) a two dimensional detector array of ferroelectric thermal detector elements having first and second portions connected to the drive circuit for biasing, each detector element of the first portion responsive to thermal energy of a scene impinging thereon to vary the voltage at its output by an amount representative of the intensity of the impinging thermal energy, and the second portion providing reference output voltages; (c) a comparator means for comparing the outputs of the first and second portions of ferroelectric thermal detector elements of the two dimensional array; and (d) a signal processing means operatively connected to the comparator for producing video signals representative of the scene whereby an image representative of the thermal radiation from the scene is presented for display.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-03-20 | 1981-09-19 | 1982-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-20 | 1985-09-19 | 1986-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-20 | 1989-09-19 | 1990-03-21 | $7700.00 | Window Closed / Lapsed |