US3639765A
Expired / Lapsed
US
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Infrared image converter
Assignee: Individual
•
Filing: 1969-07-01
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Granted: 1972-02-01
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Expires: 1989-07-01
Abstract
Abstract Device for converting light in the infrared portion of the spectrum into visible light based on the phenomenon of thermal quenching of visible fluorescence comprising a conversion screen which contains an ultraviolet irradiated temperature-sensitive phosphor.
Inventors
- 👤 Marcos Kleinerman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 01:35
CPC Classifications
H; H04; H04N; H04N23/00; H04N23/20; H04N23/23
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
189 words
An infrared image converter comprising a screen having applied thereon a phosphor, said phosphor being sensitive when irradiated with short wavelength light in a predetermined spectrum, said phosphor being comprised of a plurality of centers of two different types identified as A centers and B centers, said phosphor fluorescing in accordance with the rate of energy transfer from said A centers to said B centers when said A centers are populated, the rate of energy transfer from said A centers to said B centers depending upon the temperature of said phosphor, energy transfer from said A centers to said B centers occurring via an energy level X which level X has an energy level higher than that of said A centers by a value of Delta E wherein Delta E is approximately an order of magnitude greater than kT, T being the temperature of the screen and k being Boltzmann''s constant, said A centers becoming populated when irradiated by short wavelengths light in said predetermined spectrum, means to focus an infrared image on said screen, and means for irradiating said screen with short wavelengths light in said predetermined spectrum.
Claim 2
Dependent Claim
189 words
An infrared image converter comprising a screen having applied thereon a phosphor, said phosphor being sensitive when irradiated with short wavelength light in a predetermined spectrum, said phosphor being comprised of a plurality of centers of two different types identified as A centers and B centers, said phosphor fluorescing in accordance with the rate of energy transfer from said A centers to said B centers when said A centers are populated, the rate of energy transfer from said A centers to said B centers depending upon the temperature of said phosphor, energy transfer from said A centers to said B centers occurring via an energy level X which level X has an energy level higher than that of said A centers by a value of Delta E wherein Delta E is approximately an order of magnitude greater than kT, T being the temperature of the screen and k being Boltzmann''s constant, said A centers becoming populated when irradiated by short wavelengths light in said predetermined spectrum, means to focus an infrared image on said screen, and means for irradiating said screen with short wavelengths light in said predetermined spectrum.
Claim 3
Dependent Claim
27 words
An infrared image converter as recited in claim 1 wherein there is provided means to maintain said phosphor screen at a temperature of 2* K. and higher.
Claim 4
Dependent Claim
38 words
An infrared image converter as recited in claim 1 wherein one of said wavelengths is in the visible spectrum whereby said screen generates a visible image and wherein said converter further comprises means to display the resulting image.
Claim 5
Dependent Claim
44 words
An infrared image converter as recited in claim 3 wherein said means to display the resulting image comprises means to generate video signals representing said image and video display means responsive to said video signals to display the image represented by said video signals.
Claim 6
Dependent Claim
37 words
An infrared image converter as recited in claim 4 wherein said means to generate video signals comprises an image orthicon tube and means to focus said visible image generated by said screen on said image orthicon tube.
Claim 7
Dependent Claim
67 words
An infrared image converter as recited in claim 4 wherein said means to irradiate said screen with short wavelength light comprises means to scan said screen with a spot of short wavelength light and wherein said means to generate a video signal comprises a light-sensitive means positioned to detect the visible light generated by said screen as it is scanned by said spot of short wavelength light.
Claim 8
Independent Claim
151 words
A device for converting light in the Infrared portion of the spectrum into visible light comprising a conversion screen containing a phosphor wherein said phosphor is comprised of a plurality of different centers of two different types identified as A centers and B centers, which fluoresce at two different wavelengths, lambda 1 and lambda 2, characterized in that at least one of said centers has a visible luminescence with a luminescence efficiency >0.1 when populated, said A center being capable of being populated by ultraviolet radiation or short wavelength light, energy transfers from said A center to said B center occuring via an energy level X which level X has an energy higher than that of said A center by a value of Delta E wherein Delta E is approximately an order of magnitude greater than kT where T is the temperature of the screen and k is the Boltzmann''s constant.
Claim 9
Independent Claim
151 words
A device for converting light in the Infrared portion of the spectrum into visible light comprising a conversion screen containing a phosphor wherein said phosphor is comprised of a plurality of different centers of two different types identified as A centers and B centers, which fluoresce at two different wavelengths, lambda 1 and lambda 2, characterized in that at least one of said centers has a visible luminescence with a luminescence efficiency >0.1 when populated, said A center being capable of being populated by ultraviolet radiation or short wavelength light, energy transfers from said A center to said B center occuring via an energy level X which level X has an energy higher than that of said A center by a value of Delta E wherein Delta E is approximately an order of magnitude greater than kT where T is the temperature of the screen and k is the Boltzmann''s constant.
Claim 10
Dependent Claim
14 words
The device as set forth in claim 7 wherein the A center is luminescent.
Claim 11
Dependent Claim
19 words
The device as set forth in claim 7 wherein both the A center and the B center are luminescent.
Claim 12
Dependent Claim
50 words
The device as set forth in claim 7 wherein the A center is nonluminescent and where the rate K of energy migration to the luminescent B center is not more than an order of magnitude different from the lifetime of the A center in the absence of the B center.
Claim 13
Dependent Claim
20 words
The device as set forth in claim 7 wherein said phosphor is a crystalline Tb3 chelate doped with Eu3 ions.
Claim 14
Dependent Claim
37 words
The device as set forth in claim 11 wherein said chelate has ligands with a triplet level T1 within approximately 300 Kaysers above the 5D4 level of Tb3 as determined from the phosphorescence spectra in organic glass.
Claim 15
Dependent Claim
20 words
A phosphor consisting essentially of crystalline terbium tetrakis (1,3 bis (p-methoxyphenyl) 1,3 propanedione) piperidine doped with the corresponding europium chelate.
Claim 16
Dependent Claim
20 words
A phosphor consisting essentially of crystalline terbium tetrakis (1,3 bis (p-methoxyphenyl) 1,3 propanedione) piperidine doped with the corresponding europium chelate.
Claim 17
Independent Claim
203 words
A device for converting light in the infrared portion of the spectrum into visible light comprising a conversion screen containing a phosphor comprised of a plurality of centers of two different types identified as A centers and B centers, characterized in that at least one type of said centers has a visible luminescence with a luminescence efficiency greater than 0.1 when populated, said A centers being capable of being populated by short wavelength type light, and with an energy transfer from said A centers to said B centers which occurs via an energy level X which level X is an energy higher than that of said A centers by a value of Delta E wherein Delta E is approximately an order of magnitude greater than kT, where T is the temperature of the screen in degrees Kelvin, said temperature being not higher than 10* K., and k is the Boltzmann constant, with said energy transfer occurring with a rate K which is not more than an order of magnitude different from the lifetime of the A centers in the absence of the B centers, and obeying the relation K C exp (- Delta E/kT) where C is a constant for a given screen.
Claim 18
Independent Claim
203 words
A device for converting light in the infrared portion of the spectrum into visible light comprising a conversion screen containing a phosphor comprised of a plurality of centers of two different types identified as A centers and B centers, characterized in that at least one type of said centers has a visible luminescence with a luminescence efficiency greater than 0.1 when populated, said A centers being capable of being populated by short wavelength type light, and with an energy transfer from said A centers to said B centers which occurs via an energy level X which level X is an energy higher than that of said A centers by a value of Delta E wherein Delta E is approximately an order of magnitude greater than kT, where T is the temperature of the screen in degrees Kelvin, said temperature being not higher than 10* K., and k is the Boltzmann constant, with said energy transfer occurring with a rate K which is not more than an order of magnitude different from the lifetime of the A centers in the absence of the B centers, and obeying the relation K C exp (- Delta E/kT) where C is a constant for a given screen.
Claim 19
Dependent Claim
74 words
The device set forth in claim 14 wherein the A centers are luminescent, and wherein the incident infrared radiation quenches the luminescence of said A centers by an amount equal to the difference IA -IA , where IA and IA are the luminescence intensities at the absolute temperatures T2 and T1 respectively, said intensities obeying the relation where IA is the intensity of the luminescence of the A centers in the absence of quenching.
Claim 20
Dependent Claim
36 words
The device set forth in claim 14 comprising a conversion screen consisting of: A. a layer of infrared absorbing material, and B. a layer of temperature sensitive phosphor deposited on said layer of infrared absorbing material.
Claim 21
Dependent Claim
39 words
The device set forth in claim 14 comprising a means for excitation of the conversion screen with short-wavelength-type visible light, and a means for converting the signal resulting from the infrared heating of the screen into a video signal.
Claim 22
Independent Claim
171 words
A device for converting light in the infrared portion of the spectrum into visible light comprising a conversion screen containing a phosphor wherein said phosphor is comprised of a plurality of different centers of two different types identified as A centers and B centers, which fluoresce at two different wavelengths, lambda 1 and lambda 2, characterized in that at least one of said centers has a visible luminescence with a luminescence efficiency > 0.1 when populated, said A center being capable of being populated by ultraviolet radiation or short wavelength light, energy transfers from said A center to said B center occurring via an energy level x which level x has an energy higher than that of said A center by a value of Delta E wherein Delta E is approximately an order of magnitude greater than kT where T is the temperature of the screen and k is the Boltzmann''s constant wherein said phosphor is crystalline terbium tetrakis (1,3 bis (p-methoxyphenyl) 1,3 propanedione) piperidine doped with the corresponding europium chelate.
Claim 23
Independent Claim
171 words
A device for converting light in the infrared portion of the spectrum into visible light comprising a conversion screen containing a phosphor wherein said phosphor is comprised of a plurality of different centers of two different types identified as A centers and B centers, which fluoresce at two different wavelengths, lambda 1 and lambda 2, characterized in that at least one of said centers has a visible luminescence with a luminescence efficiency > 0.1 when populated, said A center being capable of being populated by ultraviolet radiation or short wavelength light, energy transfers from said A center to said B center occurring via an energy level x which level x has an energy higher than that of said A center by a value of Delta E wherein Delta E is approximately an order of magnitude greater than kT where T is the temperature of the screen and k is the Boltzmann''s constant wherein said phosphor is crystalline terbium tetrakis (1,3 bis (p-methoxyphenyl) 1,3 propanedione) piperidine doped with the corresponding europium chelate.
Claim 24
Dependent Claim
16 words
The device as set forth in claim 18 wherein said screen contains a layer of graphite.
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) | 1975-01-31 | 1975-08-02 | 1976-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-31 | 1979-08-02 | 1980-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-31 | 1983-08-02 | 1984-02-01 | $7700.00 | Window Closed / Lapsed |