US3749823A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal processing circuit
Assignee: Enterprises Inc
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Filing: 1971-11-26
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Granted: 1973-07-31
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Expires: 1991-11-26
Abstract
Abstract Thermal ground data and thermal reference data acquired by an airborne scanner are recorded on magnetic tape along with timing signals synchronized with the scanning. At some later time, the signals are played back and processed to produce a color image on a line-scanned cathode ray tube and the image is recorded on a continuous color film strip. Ground data signals are processed by a particular analog-to-digital converter to provide digital signals according to the instantaneous level of the thermal ground data compared to discrete reference levels which in turn are calibrated according to the thermal reference data. The digital signals gate color guns in the cathode ray tube at fixed intensity levels so that the color image is composed of a predetermined number of colors.
Inventors
- 👤 D Warner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:04
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/43
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
313 words
Apparatus for use in processing analog signals to selectively develop a plurality of digital signals representing a first predetermined number of amplitude levels of said analog signals comprising a first reference source providing a first electrical signal representing a first reference level, a second reference soUrce providing a second electrical signal representing a second reference level, first voltage divider means having a second predetermined number of serially connected impedance means, first circuit means coupling said first and said second reference sources to said first voltage divider means, comparator circuit means including a plurality of individual level detection circuit means each of which has a reference level input and an analog signal input, said reference inputs being connected to said first voltage divider means at respective different points spaced electrically therealong between said impedance means, said signal inputs of all of said level detection means being adapted to be energized by said analog signals, each of said detection circuit means being operable to generate a respective digital signal when said analog signals exceed a respective reference input at each detection circuit means, and output circuit means responsive to said digital signals for developing output signals according to preselected combinations of said digital circuits, and wherein said first circuit means comprises second voltage divider means having a third predetermined number of serially connected impedance means, opposite ends of said second voltage divider means being electrically connected to said first and said second source means respectively, said second divider means having a plurality of taps spaced electrically therealong between said impedance means, and first and second selector switch means each having a plurality of positions for selectively connecting each one of said taps to one end of said first divider means via said first switch means and each one of said taps to an opposite end of said first divider means via said second switch means.
Claim 2
Dependent Claim
313 words
Apparatus for use in processing analog signals to selectively develop a plurality of digital signals representing a first predetermined number of amplitude levels of said analog signals comprising a first reference source providing a first electrical signal representing a first reference level, a second reference soUrce providing a second electrical signal representing a second reference level, first voltage divider means having a second predetermined number of serially connected impedance means, first circuit means coupling said first and said second reference sources to said first voltage divider means, comparator circuit means including a plurality of individual level detection circuit means each of which has a reference level input and an analog signal input, said reference inputs being connected to said first voltage divider means at respective different points spaced electrically therealong between said impedance means, said signal inputs of all of said level detection means being adapted to be energized by said analog signals, each of said detection circuit means being operable to generate a respective digital signal when said analog signals exceed a respective reference input at each detection circuit means, and output circuit means responsive to said digital signals for developing output signals according to preselected combinations of said digital circuits, and wherein said first circuit means comprises second voltage divider means having a third predetermined number of serially connected impedance means, opposite ends of said second voltage divider means being electrically connected to said first and said second source means respectively, said second divider means having a plurality of taps spaced electrically therealong between said impedance means, and first and second selector switch means each having a plurality of positions for selectively connecting each one of said taps to one end of said first divider means via said first switch means and each one of said taps to an opposite end of said first divider means via said second switch means.
Claim 3
Dependent Claim
20 words
The apparatus set forth in claim 1 wherein said first and said second reference sources are fixed direct-current level sources.
Claim 4
Dependent Claim
39 words
The apparatus set forth in claim 1 wherein said first and said second reference sources each comprise a sample-and-hold circuit responsive to respective varying reference signals and respective strobe signals to provide said first and said second reference levels.
Claim 5
Dependent Claim
16 words
The apparatus set forth in claim 1 wherein said second predetermined number is at least six.
Claim 6
Dependent Claim
17 words
The apparatus set forth in claim 4 wherein said second predetermined number is less than approximately eighteen.
Claim 7
Dependent Claim
14 words
The apparatus set forth in claim 4 wherein said third predetermined number is six.
Claim 8
Dependent Claim
17 words
The apparatus set forth in claim 6 wherein said third predetermined number is less than approximately eighteen.
Claim 9
Dependent Claim
19 words
The apparatus set forth in claim 1 wherein said third predetermined number is equal to said second predetermined number.
Claim 10
Dependent Claim
95 words
The apparatus set forth in claim 1 wherein said output circuit means comprises a resistive summing network including a first plurality of resistive means each of which is connected to an output of a respective detection circuit means and further including a common resistance means adapted to sum digital signals from said resistive means so that the level of said output signals varies in accordance with the number of actuated level detection means, and wherein said output circuit means further comprises a black-and-white display device responsive to said output signals to generate a grey-scale image.
Claim 11
Dependent Claim
68 words
The apparatus set forth in claim 1 wherein said output circuit means comprises a plurality of gating circuit means adapted to respond to selective combinations of actuated level detection means to provide said output signals, and wherein said output circuit means further comprises display means having electron beam generating means responsive to said output signals to generate a display at intensity levels fixed by said gating circuit means.
Claim 12
Dependent Claim
231 words
Apparatus for processing analog signals to selectively develop digital signals representing a plurality of different amplitude ranges of said analog signal or a plurality of amplitude subranges within one or more of said amplitude ranges Comprising reference source means providing first and second references, first voltage divider means having impedance means with a plurality of taps spaced electrically therealong, said first voltage divider means being adapted to be energized from said reference source means, second voltage divider means also including impedance means, switch means having a plurality of positions for connecting said second voltage divider means across selected taps on said first voltage divider means to thereby establish reference levels at points spaced electrically along said second voltage divider, the value of said reference levels being determined by those taps selected by said switch means, comparator circuit means including a plurality of level detection circuit means each of which has a reference input and an analog signal input, each of said reference inputs being connected to a respective one of said points on said second voltage divider, said signal inputs being adapted to be energized by said analog signals, each of said detection circuit means being responsive to said analog signals and its respective reference level from said second voltage divider means to cause said comparator circuit means to generate said digital signals when said analog signals exceed said reference levels.
Claim 13
Dependent Claim
231 words
Apparatus for processing analog signals to selectively develop digital signals representing a plurality of different amplitude ranges of said analog signal or a plurality of amplitude subranges within one or more of said amplitude ranges Comprising reference source means providing first and second references, first voltage divider means having impedance means with a plurality of taps spaced electrically therealong, said first voltage divider means being adapted to be energized from said reference source means, second voltage divider means also including impedance means, switch means having a plurality of positions for connecting said second voltage divider means across selected taps on said first voltage divider means to thereby establish reference levels at points spaced electrically along said second voltage divider, the value of said reference levels being determined by those taps selected by said switch means, comparator circuit means including a plurality of level detection circuit means each of which has a reference input and an analog signal input, each of said reference inputs being connected to a respective one of said points on said second voltage divider, said signal inputs being adapted to be energized by said analog signals, each of said detection circuit means being responsive to said analog signals and its respective reference level from said second voltage divider means to cause said comparator circuit means to generate said digital signals when said analog signals exceed said reference levels.
Claim 14
Dependent Claim
38 words
The apparatus set forth in claim 11 wherein said reference source comprises a source of varying reference signals and a sample-and-hold circuit responsive to said varying signals and to strobe signals to provide said first and second references.
References Cited (Backward Citations)
US3193838A
Cited
US3644667A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |