# US 2013/0278140 A1 · Electrodeless plasma lamp utilizing acoustic modulation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0278140 A1 - Document ID: US20130278140A1 - Status: Published application - Kind: A1 - Application number: 13/866,496 - Filed: 2013-04-19 - Published: 2013-10-24 - Earliest claimed: 2012-04-19 - Assignees: Luxim Corporation - Applicants: Luxim Corporation - Inventors: Sandeep Mudunuri; Marc DeVincentis; Abdeslam Hafidi; Walter P. Lapatovich - Web page: https://patentgrep.com/patent/US20130278140A1 ## CPC - H05H 1/46: using applied electromagnetic fields, e.g. high frequency or microwave energy (H05H1/26 takes precedence) - H01J 61/125: {having an halogenide as principal component} - H01J 65/042: {by an external electromagnetic field} - H05B 41/2806: {with semiconductor devices and specially adapted for lamps without electrodes in the vessel, e.g. surface discharge lamps, electrodeless discharge lamps} - Y02B 20/00: Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps - H05H: PLASMA TECHNIQUE (apparatus or processes specially adapted for producing X-rays H05G2/00); PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract An electrodeless plasma lamp is described that employs acoustic resonance. The plasma lamp includes a metal enclosure having a conductive boundary forming a resonant structure, and a radio frequency (RF) feed to couple RF power from an RF power source into the resonant cavity. A bulb is received at least partially within an opening in the metal enclosure. The bulb contains a fill that forms a light emitting plasma when the power is coupled to the fill. The RF power source includes a controller to modulate the RF power to induce acoustic resonance in the plasma. ## Claims ### Claim 1 An electrodeless plasma lamp comprising: a metal enclosure having a conductive boundary forming a resonant structure; a radio frequency (RF) feed to couple RF power from an RF power source into the resonant cavity; a bulb containing a fill that forms a light emitting plasma when the power is coupled to the fill, the bulb being received at least partially within an opening in the metal enclosure; and a controller to modulate the RF power to induce acoustic resonance in the plasma. ### Claim 2 (depends on 1) The plasma lamp of claim 1, wherein the controller modulates the power to excite at least one acoustic resonance mode in a plasma arc formed by the plasma. ### Claim 3 (depends on 2) The plasma lamp of claim 2, wherein the acoustic resonance modifies a position of the plasma arc, the plasma arc being position closer to an exposed bulb wall when the RF power is modulated than when the RF is not modulated. ### Claim 4 (depends on 2) The plasma lamp of claim 2, wherein the acoustic resonance modifies a temperature profile of the plasma arc. ### Claim 5 (depends on 1) The plasma lamp of claim 1, wherein the fill includes metallic mercury in combination with one or more metal halide salts selected from the group consisting of TmX3, HoX3, DyX3, CeX3, and InX3, where the X=chlorine, bromine or iodine. ### Claim 6 (depends on 1) The plasma lamp of claim 1, wherein the fill includes an inert starting gas selected from the group consisting of Ar, Kr and Xe. ### Claim 7 (depends on 1) The plasma lamp of claim 1, wherein the controller modulates the power to excite acoustic resonance at a first radial acoustic mode. ### Claim 8 (depends on 1) The plasma lamp of claim 1, wherein the controller modulates the RF power at a modulation frequency, the controller being further configured to sweep a modulation frequency to operate the plasma lamp partially in a stable range of frequencies and partially in an unstable range of frequencies. ### Claim 9 (depends on 8) The plasma lamp of claim 8, wherein an envelope of the RF power is modulated at a frequency of between 100 Hz and 200 000 Hz, the stable range of frequencies being between 80 kHz and 100 kHz, and the unstable range of frequencies being between 60 kHz and 90 kHz on the low side and 90 kHz and 120 kHz on the high side. ### Claim 10 (depends on 1) The plasma lamp of claim 1, wherein the controller is configured to sweep a modulation frequency between a low modulation frequency and high modulation frequency. ### Claim 11 (depends on 10) The plasma lamp of claim 10, wherein the low modulation frequency is about 50 KHz and the high modulation frequency is about 120 KHz. ### Claim 12 (depends on 11) The plasma lamp of claim 11, wherein the low modulation frequency is about 84 KHz and the high modulation frequency is about 92 KHz. ### Claim 13 (depends on 10) The plasma lamp of claim 10, wherein the modulation frequency is an acoustic resonant frequency for the bulb. ### Claim 14 (depends on 1) The plasma lamp of claim 1, wherein the modulation is pulse width modulation. ### Claim 15 (depends on 14) The plasma lamp of claim 14, wherein the pulse width modulation has a duty factor of between about 0.5 and 1. ### Claim 16 (depends on 15) The plasma lamp of claim 15, wherein the pulse width modulation has a duty factor of between about 0.8 and 0.9. ### Claim 17 (depends on 14) The plasma lamp of claim 14, wherein the controller is configured to sweep a duty cycle of the pulse width modulation. ### Claim 18 (depends on 1) The plasma lamp of claim 1, wherein the modulation is sawtooth modulation. ### Claim 19 (depends on 1) The plasma lamp of claim 1, wherein a frequency of modulation of the RF power is less that a carrier frequency of the RF power. ### Claim 20 (depends on 1) The plasma lamp of claim 1, wherein a difference between a frequency of the RF power is more than one octave from a frequency of the acoustic modulation. ### Claim 21 (depends on 1) The plasma lamp of claim 1, wherein the controller is configured to determine a lamp volatility resulting from modulation of the RF power, the volatility indicating a magnitude of flicker of a plasma arc. ### Claim 22 (depends on 21) The plasma lamp of claim 21, wherein the controller adjusts the modulation frequency based on the determined volatility. ### Claim 23 A method of powering a plasma lamp, the method comprising: generating RF power at resonant frequency for a resonant structure, wherein the RF power is modulated at a modulation frequency; coupling the power into the resonant structure, the resonant structure including a metal enclosure having a conductive boundary; coupling the power from the resonant structure to a bulb containing a fill that forms a light emitting plasma when the power is coupled to the fill, the bulb being received at least partially within an opening in the metal enclosure; and causing acoustic resonance in the plasma induced by the modulation. ### Claim 24 (depends on 23) A method of claim 23, further comprising sweeping the modulation frequency between a low modulation frequency and high modulation frequency. ### Claim 25 (depends on 24) A method of claim 24, wherein the low modulation frequency is about 50 KHz and the high modulation frequency is about 120 KHz.