US4075532A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cool-white fluorescent lamp with phosphor having modified spectral energy distribution to improve luminosity thereof
Assignee: General Electric Co
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Filing: 1976-06-14
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Granted: 1978-02-21
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Expires: 1996-06-14
Abstract
Abstract An improved cool-white fluorescent lamp utilizes a particular two-component phosphor combination exhibiting a narrow "blue" emission spectrum and a broad "yellow" emission spectrum to achieve improved luminous efficacy. In one preferred embodiment, the combination is a blended mixture of europium activated strontium chlorapatite with manganese and antimony coactivated calcium fluorapatite phosphors.
Inventors
- 👤 William W. Piper
- 👤 Jerome S. Prener
- 👤 George R. Gillooly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:18
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/0855; C09K11/0861; C09K11/0866; C09K11/74; C09K11/75; C09K11/76; C09K11/77; C09K11/7728; C09K11/7734; C09K11/7737; C09K11/7738; C09K11/7739; H; H01; H01J; H01J61/00; H01J61/02; H01J61/38; H01J61/42; H01J61/44
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
158 words
In a fluorescent lamp of the type having a sealed envelope enclosing means to generate a low-pressure mercury discharge within said envelope, and a coating contained within said envelope for conversion of at least a portion of the radiation emitted from said discharge to visible light having a white color, the improved coating comprising: a first phosphor having a relatively broad emission spectrum with a mean wavelength in a yellow portion of the visible spectrum, wherein said first phosphor is Ca 10-w-x-y Cd w Mn x Sb y (PO 4 ) 6 F 2-y O y where w is in the approximate range 0.0-0.2, x is in the approximate range 0.25-0.50 and y is in the approximate range 0.02-0.2; a second phosphor having a relatively narrow emission spectrum in a blue portion of the visible spectrum; said first and second phosphors being uniformly blended together in a porportional relationship preselected to provide increased luminous efficacy for said mixture.
Claim 2
Dependent Claim
158 words
In a fluorescent lamp of the type having a sealed envelope enclosing means to generate a low-pressure mercury discharge within said envelope, and a coating contained within said envelope for conversion of at least a portion of the radiation emitted from said discharge to visible light having a white color, the improved coating comprising: a first phosphor having a relatively broad emission spectrum with a mean wavelength in a yellow portion of the visible spectrum, wherein said first phosphor is Ca 10-w-x-y Cd w Mn x Sb y (PO 4 ) 6 F 2-y O y where w is in the approximate range 0.0-0.2, x is in the approximate range 0.25-0.50 and y is in the approximate range 0.02-0.2; a second phosphor having a relatively narrow emission spectrum in a blue portion of the visible spectrum; said first and second phosphors being uniformly blended together in a porportional relationship preselected to provide increased luminous efficacy for said mixture.
Claim 3
Dependent Claim
29 words
The improved coating of claim 1, wherein said second phosphor is Sr 10-z Eu z (PO 4 ) 6 Cl 2 wherein z is in the approximate range 0.02-0.2.
Claim 4
Dependent Claim
39 words
The improved coating of claim 2, wherein said coating contains a quantity of said second phosphor sufficient to match the emission spectra of said first phosphor to a cool white color point having trichromatic coordinates of approximately X=0.377, Y=0.382.
Claim 5
Dependent Claim
24 words
The improved coating of claim 3, wherein the mol fraction of manganese in said first phosphor is varied to achieve said cool-white color point.
Claim 6
Dependent Claim
35 words
The improved coating of claim 3, wherein said second phosphor is in the range of 4-11% by weight of said coating, said first phosphor being in the range of 89-96% by weight of said coating.
Claim 7
Dependent Claim
29 words
The improved coating of claim 5, wherein said second phosphor is approximately 6% by weight of said coating, said first phosphor being approximately 94% by weight of said coating.
Claim 8
Dependent Claim
20 words
The improved coating of claim 3, wherein w=0.10 ± 0.03, x=0.32 ± 0.03, y=0.07 ± 0.02 and z=0.14 ± 0.05.
Claim 9
Dependent Claim
40 words
The improved coating of claim 1, wherein said second phosphor is Ba 1-z Eu z Mg 2 Al 22 O 37 wherein z is in the approximate range 0.1-0.4, said second phosphor having a peak emission of approximately 450 nanometers.
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) | 1981-02-20 | 1981-08-22 | 1982-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-20 | 1985-08-22 | 1986-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-20 | 1989-08-22 | 1990-02-21 | $7700.00 | Window Closed / Lapsed |