Electrodeless lamp system and methods of operation

Patent metadata

Field	Value
Publication number	US-10475636-B2
Application number	US-201715719482-A
Country	US
Kind code	B2
Filing date	Sep 28, 2017
Priority date	Sep 28, 2017
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

An embodiment of a system includes an RF signal source, a first electrode, a second electrode, and a cavity configured to receive an electrodeless bulb. The RF signal source is configured to generate an RF signal. The first electrode is configured to receive the RF signal and to convert the RF signal into electromagnetic energy that is radiated by the first electrode. The cavity is defined by first and second boundaries that are separated by a distance that is less than the wavelength of the RF signal so that the cavity is sub-resonant. The first electrode is physically positioned at the first boundary, and the second electrode is physically positioned at the second boundary. The first electrode, the second electrode, and the cavity form a structure that is configured to capacitively couple the electromagnetic energy into the electrodeless bulb when the electrodeless bulb is positioned within the cavity.

First claim

What is claimed is:

1. A system comprising:
a radio frequency (RF) signal source configured to generate an RF signal;
a first electrode electrically coupled to the RF signal source, wherein the first electrode is configured to receive the RF signal and to convert the RF signal into electromagnetic energy that is radiated by the first electrode;
a second electrode; and
a cavity configured to receive an electrodeless bulb that has an outer diameter, wherein the cavity is defined by first and second boundaries that are separated by a distance that is greater than the outer diameter of the electrodeless bulb and that is less than the wavelength of the RF signal so that the cavity is sub-resonant, wherein the first electrode is physically positioned at the first boundary, wherein the second electrode is physically positioned at the second boundary, and wherein the first electrode, the second electrode, and the cavity form a structure that is configured to capacitively couple the electromagnetic energy into and entirely across the outer diameter of the electrodeless bulb, when the electrodeless bulb is positioned within the cavity between the first and second electrodes.

2. The system of claim 1 , wherein the distance is less than half the wavelength of the RF signal.

3. The system of claim 2 , wherein the distance is less than one 50th the wavelength of the RF signal.

4. The system of claim 3 , wherein the distance is less than one 100th the wavelength of the RF signal.

5. The system of claim 1 , wherein the distance is in a range between 10 centimeters and 3.0 meters.

6. The system of claim 1 , wherein:
the first electrode has a rod shape with a conductive outer surface; and
the second electrode has a tubular shape with a conductive inner surface, and wherein the distance is defined by a distance between the outer surface of the first electrode and the inner surface of the second electrode.

7. The system of claim 1 , wherein the first electrode is configured as a first planar conductive structure, and the second electrode is configured as a second planar conductive structure.

8. The system of claim 1 , wherein the second electrode includes a plurality of holes to enable light or radiation to exit the cavity.

9. The system of claim 1 , wherein the RF signal has a frequency in a range from 10 megahertz (MHz) to 3.0 gigahertz (GHz).

10. The system of claim 1 , wherein the RF signal source is configured to generate the RF signal to produce a voltage across the first and second electrodes in a range of 90 volts to 3000 volts.

11. The system of claim 1 , wherein the cavity is configured to receive multiple electrodeless bulbs.

12. The system of claim 1 , wherein the system is selected from an ambient lighting system, an air purification system, and a liquid purification system.

13. The system of claim 1 , further comprising:
a variable resonant circuit electrically coupled between an output of the RF signal source and the first electrode; and
a system controller configured to establish and modify a resonant frequency of the variable resonant circuit through control signals that the system controller sends to the variable resonant circuit.

14. The system of claim 13 , further comprising:
an electric field sensor configured to sense an electromagnetic field intensity within or proximate to the cavity, and to send a sensor signal to the system controller indicating the electromagnetic field intensity,
wherein the system controller is configured to modify the resonant frequency of the variable resonant circuit based on the electromagnetic field intensity indicated in the sensor signal.

15. The system of claim 13 , further comprising:
a radiation intensity sensor configured to sense a radiation intensity within or proximate to the cavity, and to send a sensor signal to the system controller indicating the radiation intensity,
wherein the system controller is configured to modify the resonant frequency of the variable resonant circuit based on the radiation intensity indicated in the sensor signal.

16. The system of claim 13 , further comprising:
a luminous intensity sensor configured to sense a luminous intensity within or proximate to the cavity, and to send a sensor signal to the system controller indicating the luminous intensity,
wherein the system controller is configured to modify the resonant frequency of the variable resonant circuit based on the luminous intensity indicated in the sensor signal.

17. The system of claim 13 , wherein the variable resonant circuit includes one or more variable passive devices selected from inductors, capacitors, and resistors.

18. A method of operating an electrodeless lamp system, the method comprising:
producing, by an RF signal source, an RF signal;
conveying the RF signal to a first electrode of a lamp excitation structure that includes the first electrode, a second electrode, and a cavity configured to receive an electrodeless bulb that has an outer diameter, wherein the cavity is defined by first and second boundaries that are separated by a distance that is greater than the diameter of the electrodeless bulb and that is less than a wavelength of the RF signal so that the cavity is sub-resonant, wherein the first electrode is physically positioned at the first boundary, wherein the second electrode is physically positioned at the second boundary, and wherein the first electrode, the second electrode, and the cavity form a structure that is configured to capacitively couple the electromagnetic energy into the electrodeless bulb when the electrodeless bulb is positioned within the cavity between the first and second electrodes; and
converting, by the first electrode, the RF signal into electromagnetic energy that is radiated by the first electrode into the cavity.

19. The method of claim 18 , further comprising:
sensing one or more of an electromagnetic field intensity, a luminous intensity, and a radiation intensity within or in proximity to the cavity;
producing a sensor signal that indicates the electromagnetic field intensity, the luminous intensity, or the radiation intensity; and
modifying a resonant frequency of a variable resonant circuit that is electrically coupled between the RF signal source and the first electrode based on the sensor signal.

20. The method of claim 19 , wherein modifying the resonant frequency is performed to increase the electromagnetic field intensity, the luminous intensity, or the radiation intensity.

Assignees

• Nxp Usa Inc

Inventors

• Do Steven
• Mongin Lionel
• Piel Pierre Marie Jean

Classifications

• H05B41/39

  continuously · CPC title

• H01J65/042 Primary

  by an external electromagnetic field · CPC title

• H05B41/2806

  with semiconductor devices and specially adapted for lamps without electrodes in the vessel, e.g. surface discharge lamps, electrodeless discharge lamps · CPC title

• H01J61/95

  Lamps with control electrode for varying intensity or wavelength of the light, e.g. for producing modulated light · CPC title

• H01J65/046

  the field being produced by using capacitive means around the vessel · CPC title