US5300860A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Capacitively coupled RF fluorescent lamp with RF magnetic enhancement
Assignee: Osram Sylvania Inc
•
Filing: 1992-10-16
•
Granted: 1994-04-05
•
Expires: 2012-10-16
Abstract
Abstract A fluorescent light source includes a fluorescent lamp having first and second electrodes at or near the ends thereof for capacitive coupling of RF electrical energy to a low pressure discharge within the fluorescent lamp and an RF source having a first output lead electrically coupled to the first electrode and a second output lead electrically coupled to the second electrode. The electrodes include circuitry for inducing an RF magnetic field within the fluorescent lamp in the region of the electrodes. The RF magnetic field improves the performance of the capacitively coupled RF light source by creating an auxiliary inductive RF discharge near the capacitive coupling electrodes. The inductive discharge locally increases the plasma density and the electrode sheath capacitance and provides a reduction in RF voltage across the capacitively coupled fluorescent lamp.
Inventors
- 👤 Valery A. Godyak
- 👤 Robert B. Piejak
- 👤 Benjamin M. Alexsandrovich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:57
CPC Classifications
H; H01; H01J; H01J65/00; H01J65/04; H01J65/042; H01J65/046; H01J61/00; H01J61/02; H01J61/54; H01J61/56; H01J65/048; H05; H05B; H05B41/00; H05B41/14; H05B41/24; H05B41/26; H05B41/28; H05B41/2806; Y; Y02; Y02B; Y02B20/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
118 words
A fluorescent light source comprising: a fluorescent lamp having first and second electrodes disposed at or near the ends thereof for capacitive coupling of RF electrical energy to a low pressure discharge within said fluorescent lamp, each of said first and second electrodes comprising a conductive layer on the outside surface of said fluorescent lamp for capacitive coupling of RF electrical energy to a discharge within said fluorescent lamp and a conductive coil disposed around said conductive layer for inducing an axial RF magnetic field within said fluorescent lamp near said electrodes; and an RF source having a first output lead electrically coupled to said first electrode and a second output lead electrically coupled to said second electrode.
Claim 2
Dependent Claim
118 words
A fluorescent light source comprising: a fluorescent lamp having first and second electrodes disposed at or near the ends thereof for capacitive coupling of RF electrical energy to a low pressure discharge within said fluorescent lamp, each of said first and second electrodes comprising a conductive layer on the outside surface of said fluorescent lamp for capacitive coupling of RF electrical energy to a discharge within said fluorescent lamp and a conductive coil disposed around said conductive layer for inducing an axial RF magnetic field within said fluorescent lamp near said electrodes; and an RF source having a first output lead electrically coupled to said first electrode and a second output lead electrically coupled to said second electrode.
Claim 3
Dependent Claim
48 words
A fluorescent light source as defined in claim 1 wherein said fluorescent lamp comprises two straight tube sections and an interconnection between said straight tube sections at or near one end, said first and second electrodes being located adjacent to each other at or near the other end.
Claim 4
Dependent Claim
148 words
A fluorescent light source comprising: a fluorescent lamp comprising two straight tube sections and an interconnection between said straight tube sections at or near one end, first and second electrodes being located adjacent to each other at or near the other end thereof for capacitive coupling of RF electrical energy to a low pressure discharge within said fluorescent lamp, each of said first and second electrodes comprising a conductive coil on the outside surface of said fluorescent lamp for inducing an axial magnetic field within said fluorescent lamp; ferromagnetic material between said straight tube sections at one or both ends of said conductive coils for increasing the magnetic field strength within said fluorescent lamp for a given current through said conductive coils; and an RF source having a first output lead electrically coupled to said first electrode and a second output lead electrically coupled to said second electrode.
Claim 5
Dependent Claim
148 words
A fluorescent light source comprising: a fluorescent lamp comprising two straight tube sections and an interconnection between said straight tube sections at or near one end, first and second electrodes being located adjacent to each other at or near the other end thereof for capacitive coupling of RF electrical energy to a low pressure discharge within said fluorescent lamp, each of said first and second electrodes comprising a conductive coil on the outside surface of said fluorescent lamp for inducing an axial magnetic field within said fluorescent lamp; ferromagnetic material between said straight tube sections at one or both ends of said conductive coils for increasing the magnetic field strength within said fluorescent lamp for a given current through said conductive coils; and an RF source having a first output lead electrically coupled to said first electrode and a second output lead electrically coupled to said second electrode.
Claim 6
Dependent Claim
27 words
A fluorescent light source as defined in claim 1 wherein said conductive coils each comprise a flat ribbon disposed on the outside surface of said fluorescent lamp.
Claim 7
Dependent Claim
24 words
A fluorescent light source as defined in claim 1 wherein said conductive coils are part of a resonant tank circuit of said RF source.
Claim 8
Dependent Claim
22 words
A fluorescent light source as defined in claim 1 wherein each conductive layer has an axial gap to prevent circumferential current flow.
Claim 9
Dependent Claim
26 words
A fluorescent light source as defined in claim 1 wherein said RF source has a frequency in the range of about 3 MHz to 300 MHz.
Claim 10
Dependent Claim
26 words
A fluorescent light source as defined in claim 1 wherein said RF source has a frequency in the range of about 10 MHz to 100 MHz.
Claim 11
Dependent Claim
30 words
A fluorescent light source as defined in claim 2 further including a lamp base for supporting said twin tube fluorescent lamp, said RF source being mounted within said lamp base.
References Cited (Backward Citations)
US2139815A
Cited
US2569154A
Cited
US3497767A
Cited
US4005330A
Cited
US4017764A
Cited
US4010400A
Cited
US4189661A
Cited
US4266167A
Cited
US4857806A
Cited
US4427923A
Cited
US4798997A
Cited
US5075603A
Cited
US5072157A
Cited
US5027041A
Cited
US5146140A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-04-04 | 1997-10-04 | 1998-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-04-04 | 2001-10-04 | 2002-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-04-04 | 2005-10-04 | 2006-04-05 | $7700.00 | Window Closed / Lapsed |