US3875473A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polychromatic electroluminescent device
Assignee: US Philips Corp
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Filing: 1973-12-11
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Granted: 1975-04-01
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Expires: 1993-12-11
Abstract
Abstract Several elementary light sources are connected in series and energized simultaneously to emit electroluminescent radiation at different wavelengths. The light flux emitted by a first source is larger than that of the second source when a current is injected into each source, and the light flux of the second source is larger than that of the first source when a current of a different intensity is injected into each source.
Inventors
- 👤 Jacques Lebailly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:28
CPC Classifications
H; H10; H10W; H10W90/00; H05; H05B; H05B33/00; H10H; H10H20/00; H10H20/80; H10H20/85; H10H20/851; H10W72/00; H10W72/01; H10W72/015; H10W72/01515; H10W72/071; H10W72/075; H10W72/50; H10W72/531; H10W72/5363; H10W72/851; H10W72/874; H10W72/884; H10W90/701; H10W90/751; H10W90/753
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
132 words
An electroluminescent device formed by several interconnected elementary light sources which are energized simultaneously and at least two of which emit electroluminescent radiations of different wavelengths, characterized in that the light flux emitted by a first source which emits a radiation of a first colour is larger than that of a second source of the device when the same current of intensity I1 is injected into each of the said sources and the light flux which is emitted by the second source which emits a radiation of a different colour is larger than that of the first source of the device when the same current of intensity I2 which differs from I1 is injected into each of the said sources, and that the light sources of the device are connected in series.
Claim 2
Dependent Claim
132 words
An electroluminescent device formed by several interconnected elementary light sources which are energized simultaneously and at least two of which emit electroluminescent radiations of different wavelengths, characterized in that the light flux emitted by a first source which emits a radiation of a first colour is larger than that of a second source of the device when the same current of intensity I1 is injected into each of the said sources and the light flux which is emitted by the second source which emits a radiation of a different colour is larger than that of the first source of the device when the same current of intensity I2 which differs from I1 is injected into each of the said sources, and that the light sources of the device are connected in series.
Claim 3
Dependent Claim
75 words
An electroluminescent device as claimed in claim 1, characterized in that it comprises at least one light source of a first colour of which the light flux is restricted to a value which is substantially constant at least for a range of current intensities of the injected current and at least one light source of a different colour of which the light flux varies in the same range of current intensities of the injected current.
Claim 4
Dependent Claim
73 words
An electroluminescent device as claimed in claim 1, characterized in that it comprises at least one light source of a first colour of which the light flux, at least for a range of current intensities of the injected current, is substantially proportional to said intensity, and a least one source of a different colour of which the light flux for the same current intensity range is a non-linear function of the injected current.
Claim 5
Dependent Claim
91 words
An electroluminescent device as claimed in claim 1, characterized in that it comprises at least one light source of a first colour of which the light flux, at least in a range of the injected current, is substantially proportional to a power n of said current intensity; n being a number exceeding 1, and at least one source of a different colour of which the light flux in the same current intensity range is a different function of the current intensity than that of said light source of the first colour.
Claim 6
Dependent Claim
68 words
An electroluminescEnt device as claimed in claim 1, characterized in that it comprises at least two light sources of different colours of which one is manufactured from a semiconductor material having a strong concentration of impurities and of which the other is manufactured from a semiconductor material having a weaker concentration of impurities with a smaller forbidden bandwidth and a smaller efficiency at a higher current intensity level.
Claim 7
Dependent Claim
59 words
An electroluminescent device as claimed in claim 1, characterized in that the light flux emitted by the source which emits a radiation of a first colour, at least at one value of the current intensity of the injected current, is larger than ten times the light flux emitted by all sources which emit a radiation of a different colour.
Claim 8
Dependent Claim
25 words
An electroluminescent device as claimed in claim 1, characterized in that several light sources are placed beside each other and as closely together as possible.
Claim 9
Dependent Claim
46 words
An electroluminescent device as claimed in claim 1, characterized in that several light sources are superimposed in decreasing value as regards the wavelength of the emitted radiation, each source being at least partly transparent to the radiation emitted by the source on which it is placed.
Claim 10
Dependent Claim
25 words
An electroluminescent device as claimed in claim 7, characterized in that it comprises an optical system for superimposing light rays emitted by the various sources.
Claim 11
Dependent Claim
19 words
An electroluminescent device as claimed in claim 9, characterized in that the various sources are covered by a cap.
Claim 12
Dependent Claim
65 words
An electroluminescent device as claimed in claim 4, characterized in that it comprises at least one diode having a p-n junction manufactured from a material which emits in the visible spectrum, and at least one diode having a p-n junction manufactured from gallium arsenide which emits an infrared radiation and which is covered with a multi-stage photo luminescent material and emits in the visible spectrum.
Claim 13
Dependent Claim
88 words
An electroluminescent device as claimed in claim 1 characterized in that it comprises at least one diode which emits a radiation having a dominant red colour at a first value of the intensity of the injected current, at least one diode which emits a radiation of a dominant yellow colour at a second value of current intensity of the injected current, and at least one light source which emits a radiation having a dominant green colour at a third value of the current intensity of the injected current.
Claim 14
Dependent Claim
89 words
An electroluminescent device as claimed in claim 1, characterized in that it comprises at least one diode which emits a radiation of a dominant red colour at a first value of current intensity of the injected current, at least one light source which emits a radiation of a dominant green colour at a second value of current intensity of the injected current, and at least one light source which emits a radiation having a dominant blue colour at a third value of the current intensity of the injected current.
Claim 15
Dependent Claim
80 words
An electroluminescent device as claimed in claim 2, characterized in that it comprises at least one diode having a p-n junction of gallium phosphide doped with zinc and oxygen which emits a radiation of red colour, and at least one light source which emits a radiation of a different colour and whose light flux varies as a function of the intensity of the current which traverses same at the values of the intensity of the current saturating the said diode.
Claim 16
Dependent Claim
99 words
An electroluminescent device as claimed in claim 3, characterized in that it comprises at least one diode having a p-n junction of a semiconductor material with direct band structure selected from the group consisting of gallium arsenide phosphide, gallium aluminum arsenide, gallium indium phosphide, indium aluminum phosphide and gallium nitride, and at least one light source which emits a radiation of a different colour and whose light flux varies as a function of the intensity of the current which traverses same according to a function different from that of the said diode in the same rangE of current intensities.
Claim 17
Dependent Claim
83 words
An electroluminescent device as claimed in claim 3, characterized in that it comprises at least one diode having a p-n junction of gallium phosphide doped with nitrogen which emits a radiation of green colour, and at least one light source which emits a radiation of a different colour and whose light flux varies as a function of the intensity of the current which traverses same according to a function different from that of the said diode in the same range of current intensities.
Claim 18
Dependent Claim
76 words
An electroluminescent device as claimed in claim 11, characterized in that it comprises at least one diode having a p-n junction of silicon-doped gallium arsenide which emits a radiation of 0.97 Mu m and which is covered with an epoxy resin in which grains of sodium yttrium fluoride NaYF4 which is doped with ytterbium and erbium are embedded, and at least one diode having a p-n junction which emits a visible radiation of a different colour.
Claim 19
Dependent Claim
73 words
An electroluminescent device as claimed in claim 5, characterized in that it comprises at least one diode having a p-n junction of indium phosphide or gallium phosphide with a concentration of impurities exceeding 1016 per cm3 which emits a radiation of a yellow colour, and at least one diode having a p-n junction of gallium arsenide phosphide with a concentration of impurities exceeding 1015 per cm3 which emits a radiation of red colour.
Claim 20
Dependent Claim
108 words
An electroluminescent device as claimed in claim 12, characterized in that it comprises arranged beside each other a diode of gallium phosphide doped with zinc and oxygen, a diode of gallium arsenide phosphide GaAs1-xPx, x being between 0.80 and 0.85, which is doped with nitrogen the emissive surface of which is five to 20 times larger than the diode of gallium phosphide, and a diode of silicon-doped gallium arsenide which is covered with an epoxy resin in which grains of sodium yttrium fluoride which is doped with ytterbium and erbium are embedded, and whose emissive surface is two to 10 times larger than the diode of gallium phosphide.
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) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |