US4135110A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical discharge lamp
Assignee: EMI Group Ltd
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Filing: 1977-09-08
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Granted: 1979-01-16
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Expires: 1997-09-08
Abstract
Abstract Electrical discharge lamps containing mixed halides of superior performance are provided by the inclusion in the lamp of a volatile complex halide compound of tin and sodium. The halide may be added as a mixture of tin and sodium halide but the complex is formed in operation of the lamp and has a much higher volatility than the constituent halides. The preferred lamps contain 5 to 100 micromoles tin and 1 to 250 micromoles sodium halide per cubic centimeter, in a gas fill containing more than 50 micromoles per c.c. mercury.
Inventors
- 👤 Alan G. Chalmers
- 👤 Frank L. Whittaker
- 👤 David O. Wharmby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:31
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/12; H01J61/18
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
67 words
In an electrical discharge lamp comprising a sealed light-transmitting envelope having arc electrodes spaced and sealed therein, leads for said electrodes and a volatile fill in said envelope, the improvement which consists in a fill comprising in combination an amount of mercury in excess of 50 μmol cm -3 , a rare gas and, at least during operation, a volatile complex halide compound of tin and sodium.
Claim 2
Dependent Claim
67 words
In an electrical discharge lamp comprising a sealed light-transmitting envelope having arc electrodes spaced and sealed therein, leads for said electrodes and a volatile fill in said envelope, the improvement which consists in a fill comprising in combination an amount of mercury in excess of 50 μmol cm -3 , a rare gas and, at least during operation, a volatile complex halide compound of tin and sodium.
Claim 3
Dependent Claim
18 words
The lamp of claim 1 wherein the amount of tin is 5 to 100 μmol cm -3 .
Claim 4
Dependent Claim
53 words
The lamp of claim 2 wherein the fill contains additional halogen atoms in a total quantity of 5 to 100 μmol cm -3 and selected from chlorine and bromine in the presence of iodine at an atomic ratio of 0.5 to 5 Cl/I or Br/I or bromine in the absence of other halogen.
Claim 5
Dependent Claim
17 words
The lamp of claim 3 wherein the fill contains 1 to 250 μmol cm -3 sodium halide.
Claim 6
Dependent Claim
35 words
The lamp of claim 5 wherein the pressure of rare gas is 5 to 100 torr at 20° C. and the quantity of mercury is in the range 50 to 150 μmol cm -3 .
Claim 7
Dependent Claim
13 words
The lamp of claim 3 wherein said atomic ratio is greater than 1.
Claim 8
Dependent Claim
12 words
The lamp of claim 6 wherein said atomic ratio is about 2:1.
Claim 9
Dependent Claim
22 words
The lamp of claim 3 wherein the total quantity of said additional halogen atoms is about 40 μmol cm -3 or more.
Claim 10
Dependent Claim
15 words
The lamp of claim 1 wherein said envelope is of polycrystalline or single crystal alumina.
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) | 1982-01-15 | 1982-07-17 | 1983-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-15 | 1986-07-17 | 1987-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-15 | 1990-07-17 | 1991-01-16 | $7700.00 | Window Closed / Lapsed |