US4366407A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Incandescent lamp with selective color filter
Assignee: LASALLE DURO-TEST LLC
•
Filing: 1980-08-01
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Granted: 1982-12-28
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Expires: 2000-08-01
Abstract
Abstract An incandescent lamp utilizing a transparent heat mirror coating on the lamp envelope for transmitting radiation in a selected portion of the visible range to produce a desired color and reflecting infrared thermal radiation back to the filament for increasing its temperature and thereby increasing its efficiency. The coating is preferably of the etalon type having a layer of an insulating material sandwiched between two layers of metal.
Inventors
- 👤 Peter Walsh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:38
CPC Classifications
H; H01; H01K; H01K1/00; H01K1/28; H01K1/32
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
116 words
An incandescent electric lamp for producing visible light of a selected color region comprising: an envelope of material which is transmissive to energy in the visible range, filament means within said envelope which incandesces in response to electrical current applied thereto to produce radiant energy in both the visible and infrared regions, means for supplying electrical current to said filament means, and a coating on said envelope formed of a discrete film of a dielectric material sandwiched between two discrete films of a metal, said films forming a composite filter for transmitting therethrough energy over only a selected portion of the visible range produced by said filament to provide a distinct color output for the lamp.
Claim 2
Dependent Claim
116 words
An incandescent electric lamp for producing visible light of a selected color region comprising: an envelope of material which is transmissive to energy in the visible range, filament means within said envelope which incandesces in response to electrical current applied thereto to produce radiant energy in both the visible and infrared regions, means for supplying electrical current to said filament means, and a coating on said envelope formed of a discrete film of a dielectric material sandwiched between two discrete films of a metal, said films forming a composite filter for transmitting therethrough energy over only a selected portion of the visible range produced by said filament to provide a distinct color output for the lamp.
Claim 3
Dependent Claim
52 words
An incandescent lamp as in claim 1 wherein said coating is reflective to energy in the infrared range produced by said filament, said envelope being optically shaped and said filament means located with respect to said envelope such that infrared energy which impinges on the envelope is reflected back to the filament.
Claim 4
Dependent Claim
19 words
An incandescent lamp as in claim 1 wherein the two metal films of the coating are of unequal thickness.
Claim 5
Dependent Claim
53 words
An incandescent lamp as in claim 1 wherein the transmission characteristic of the coating has a plurality of bands each centered at a different wavelength, said coating transmitting visible light in a selected region located at the center λ o of the transmission band of longest wavelength with a transmission bandwidth of Δλ.
Claim 6
Dependent Claim
53 words
An incandescent lamp as in claim 3 wherein the transmission characteristic of the coating has a plurality of bands each centered at a different wavelength, said coating transmitting visible light in a selected region located at the center λ o of the transmission band of longest wavelength with a transmission bandwidth of Δλ.
Claim 7
Dependent Claim
21 words
An incandescent lamp as in claim 4 wherein Δλ is defined on the longer wavelength side of the selected transmission band.
Claim 8
Dependent Claim
21 words
An incandescent lamp as in claim 5 wherein Δλ is defined on the longer wavelength side of the selected transmission band.
Claim 9
Dependent Claim
44 words
An incandescent lamp as in either of claims 6 or 7 wherein Δλ is the wavelength between λ o and the point of the selected transmission band where the transmission of the coating is approximately one-half that of its transmission at λ o .
Claim 10
Dependent Claim
38 words
An incandescent lamp as in claim 8 wherein the transmission band of the coating is selected from the group of wavelengths in nanometers consisting of: ______________________________________
λ.sub.0 (about)
Δλ (about)
______________________________________
440 6
520 4
660 6
______________________________________
Claim 11
Dependent Claim
45 words
An incandescent lamp as in either of claims 1 or 3 wherein the transmission characteristic of the coating has a plurality of bands each centered at a different wavelength, said coating transmitting visible light in a selected wavelength region which spans two of said bands.
Claim 12
Dependent Claim
32 words
An incandescent lamp as in claim 10 wherein the peak of the longest wavelength band is in the infrared range and the peak of the other band is in the visible range.
Claim 13
Dependent Claim
25 words
An incandescent lamp as in claim 10 wherein the selected wavelength region is from the highest wavelength transmission band to the next lowest wavelength transmission.
Claim 14
Dependent Claim
15 words
An incandescent lamp as in claim 10 wherein the selected wavelength region transmits "white" light.
Claim 15
Dependent Claim
36 words
An incandescent lamp as in claim 11 wherein the peak of the other band occurs in the region of "blue" light and transmission of energy is continuous between the peaks of the first and second bands.
Claim 16
Dependent Claim
22 words
An incandescent lamp as in claim 14 wherein the transmission characteristic has a minimum in the visible range between the two peaks.
Claim 17
Dependent Claim
21 words
An incandescent lamp as in claim 4 wherein Δλ is defined on the longer wavelength side of the selected transmission band.
Claim 18
Dependent Claim
25 words
An incandescent lamp as in claim 11 wherein the selected wavelength region is from the highest wavelength transmission band to the next lowest wavelength transmission.
Claim 19
Dependent Claim
26 words
An incandescent electric lamp as in either of claims 1 or 2 wherein the metal is selected from the group consisting of copper, gold and silver.
Claim 20
Dependent Claim
29 words
An incandescent electric lamp as in either of claims 1 or 2 wherein the dielectric material is selected from the group consisting of titanium dioxide, magnesium fluoride and cryolite.
Claim 21
Dependent Claim
25 words
An incandescent electric lamp as in claim 18 wherein the dielectric material is selected from the group consisting of titanium dioxide, magnesium fluoride and cryolite.
References Cited (Backward Citations)
US3312814A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-12-27 | 1986-06-28 | 1986-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-27 | 1990-06-28 | 1990-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-27 | 1994-06-28 | 1994-12-28 | $7700.00 | Window Closed / Lapsed |