Patent Grant
9236238
The present invention is directed to devices and methods for generating light with plasma lamps. More particularly, the present invention provides plasma lamps driven by a radio-frequency source without the use of electrodes inside the bulb and related methods. In a specific embodiment, a coaxial type coupling module is used to drive an electrodeless bulb. Merely by way of example, such plasma lamps can be applied to applications such as stadiums, security, parking lots, military and defense, street lighting, large and small buildings, vehicle headlamps, aircraft landing, bridges, warehouses, UV water treatment, agriculture, architectural lighting, stage lighting, medical illumination, microscopes, projectors and displays, any combination of these, and the like.
Plasma lamps provide extremely bright, broadband light, and are useful in applications such as general illumination, projection systems, and industrial processing. The typical plasma lamp manufactured today contains a mixture of gas and trace substances that is excited to form a plasma using a high current passed through closely-contacting electrodes. This arrangement, however, suffers from deterioration of the electrodes inside the bulb, and therefore a limited lifetime. Other limitations also exist with conventional plasma lamps.
From the above, it is seen that techniques for improving plasma lamps are highly desirable.
According to the present invention, techniques directed to devices and methods for generating light with plasma lamps are provided. More particularly, the present invention provides plasma lamps driven by a radio-frequency source without the use of electrodes inside the gas filled vessel (bulb) and related methods. As an example, the radio-frequency source is coupled to the gas filled vessel using a coaxial type resonator/waveguide. In one or more embodiments, the resonator/waveguide is not made using or is generally free from a dielectric material such as alumina or quartz.
In a preferred embodiment, the coupling element that couples RF energy to the coaxial type resonator/waveguide is grounded at one end of the coupling element. In addition the arc of the gas filled vessel (bulb) is substantially not surrounded by the body of the resonator/waveguide allowing the use of reflectors and other optical components used in designing luminaries. That is, the gas filled vessel is substantially includes the arc, which is substantially free from any mechanical blockage by one or more portions of the body of the coaxial type resonator/waveguide, which allows the use of such reflectors and other optical components. Merely by way of example, such plasma lamps can be applied to applications such as stadiums, security, parking lots, military and defense, street lighting, large and small buildings, bridges, warehouses, agriculture, UV water treatment, architectural lighting, stage lighting, medical illumination, microscopes, projectors and displays, any combination of these, and the like. Of course, there can be other variations, modifications, and alternatives.
In a specific embodiment, the present invention provides a plasma electrodeless lamp. The lamp comprises a coaxial type resonator/waveguide body receiving the gas-filled vessel (bulb) at one end of the coaxial type resonator/waveguide by the center conductor. The other end of the center conductor of the coaxial resonator/waveguide is conductively connected to ground (or “shield” of the coaxial waveguide/resonator). An input coupling element couples RF energy to the center conductor of the coaxial waveguide/resonator through a section of the coaxial resonator/waveguide with the ground conductor (shield) removed. One end of the input coupling element is connected to an RF source while the other end is conductively connected to ground. Electromagnetic energy is RF-coupled between the input coupling element and the center conductor of the coaxial type waveguide/resonator. Electromagnetic energy is capacitively, or inductively or a combination of inductively and capacitively coupled to the bulb through the center conductor of the coaxial type waveguide/resonator. The lamp may further comprise a reflector to direct the luminous output of the bulb in the bulb-coupling element assembly. Alternatively, the lamp is free from any reflector design or the like. The lamp further may comprise a ground strap to conductively connect to or be coupled to the top of the bulb and to the conductive lamp body. Alternatively, the ground strap may conductively connect or be coupled to the top of the bulb-coupling element assembly to the reflector, which in turn is conductively connected to the lamp body.
In a specific embodiment, the present invention provides an alternative electrodeless plasma lamp. The lamp includes a gas filled vessel having a transparent or translucent body configured by an inner region and an outer surface region with a cavity being defined within the inner region. The gas filled vessel typically contains an inert gas such as Argon or Xenon (or combination of inert gases) and one or more light emitters such as Mercury, Indium Bromide, Sulfur, Cesium Bromide, among others. The gas filled vessel is closely received by the center conductor of a coaxial type resonator/waveguide. The other end of the center conductor of the coaxial type resonator/waveguide is conductively connected to the ground/shield of the coaxial resonator/waveguide. The center conductor of the coaxial type waveguide/resonator can be surrounded by air or a dielectric material. A portion of the shield (ground) of the coaxial waveguide/resonator is removed. An input coupling element couples RF energy to the center conductor of the coaxial resonator/waveguide through this opening in the shield/ground. One end of the input coupling element is connected to an RF source including an oscillator and an amplifier. The other end of the input coupling element is connected electrically to or is coupled to the shield/ground of the coaxial resonator/waveguide. The center conductor of the coaxial waveguide/resonator couples the RF energy to the gas filled vessel capacitively, inductively, or a combination of capacitively and inductively. The dimensions of the input coupling element and the center conductor of the coaxial resonator/waveguide and the separation between them can be adjusted to optimize RF energy transfer between the RF source and the gas filled vessel (bulb). RF energy ionizes the gas inside the bulb and vaporizes the light emitter(s) resulting in electromagnetic radiation from the bulb in the visible and/or ultra violet and/or infrared part of the spectrum.
In one or more embodiments, the resonant frequency of the coaxial type resonator/waveguide depends on other parameters, alone or in combination. Such parameters may include the length of the center conductor of the coaxial waveguide/resonator or the inductance of the center conductor, the diameter of the center conductor, the separation between the center conductor along its length and the ground (shielding) walls of resonator/waveguide as well as the dielectric constant of material between them resulting in changing the capacitance of the resonator, alone or in combination, among others. By increasing the effective capacitance and inductance of the coaxial type resonator/waveguide the dimensions of the resonator or the resonant frequency of the resonator can be changed.
In preferred embodiments, the plasma lamp apparatus comprises a spatial gap disposed between an input RF coupling element and the center conductor of the coaxial type resonator/waveguide, which is coupled to a gas filled vessel.
A device is also provided in one or more embodiments. The device comprises an RF source; an electromagnetic resonator structure coupled to at least one RF coupling element configured to introduce RF energy into the electromagnetic resonator structure and a bulb comprising a fill material. The bulb is coupled to the electromagnetic resonator structure to emit electromagnetic energy from a spectrum of at least ultra-violet, visible, or infrared; and an exposed region of the bulb protruding outside of the electromagnetic resonator structure to cause a substantial portion of the electromagnetic radiation to be emitted from exterior surfaces of the bulb without reflection from the electromagnetic resonator structure. In one or more embodiments, the spectrum may include combinations of the above as well as other regions. Of course, there can be various combinations, alternatives, and variations.
According to an embodiment, the present invention provides a plasma lamp apparatus having a co-axial configuration. The apparatus includes a radio frequency coupling element having a first portion and a second portion, a length is defined between the first portion and the second portion. The apparatus includes a bulb comprising a fill material coupled to the first portion. The apparatus includes a radio frequency source coupled to the second portion of the radio frequency coupling element. The apparatus includes a housing structure configured from the first portion to the second portion to enclose the length of the radio frequency coupling element. The apparatus includes a reference potential coupled to the housing structure.
According to another embodiment, the present invention provides a plasma lamp apparatus having a co-axial configuration. The apparatus includes a gas filled vessel having a transparent or translucent body configured by an inner region and an outer surface region, a cavity being defined within the inner region. The apparatus includes a first cylindrical member having a first end and a second end, the first end being coupled to the gas filled vessel. The apparatus includes a second cylindrical member having third end and a fourth end, the third end being coupled to second end. The apparatus includes an RF source electrically coupled to the second cylindrical member near the third end. The apparatus includes a resonator body enclosing the first and second cylindrical member, the resonator body being adapted to providing shielding for the first and second cylindrical members. The apparatus includes a reference voltage electrically coupled to the second cylindrical member near the fourth end.
According to yet another embodiment, the present invention provides a plasma lamp apparatus. The apparatus includes a vessel being filled with a filling material, the vessel being free from electrode. The apparatus includes a center conductive member having a first end and a second end, the center conductive member being characterized by a substantially cylindrical shape centered on a first axis, the first end being coupled to the vessel. The apparatus includes an outer conductive member, the outer conductive member being characterized by a substantially cylindrical shape centered on the first axis, the outer conductive member having an inner volume, the center conductive member being positioned inside the inner volume, the outer conductive member being associated with one or more resonance frequencies. The apparatus includes a first ground potential, the first ground potential being electrically coupled to the second end of the center conductive member.
According to yet another embodiment, the present invention provides a plasma lamp apparatus. The apparatus includes a vessel being filled with a filling material, the vessel being free from electrode. The apparatus includes a center conductive member having a first end and a second end, the center conductive member being characterized by a substantially cylindrical shape centered on a first axis, the first end being coupled to the vessel. The apparatus includes an outer conductive member, the outer conductive member being characterized by a substantially cylindrical shape centered on the first axis, the outer conductive member having an inner volume, the center conductive member being positioned inside the inner volume, the outer conductive member being associated with one or more resonance frequencies. The apparatus includes a first ground potential, the first ground potential being electrically coupled to the second end of the center conductive member.
According to yet another embodiment, the present invention provides a plasma lamp apparatus. The apparatus includes a vessel being filled with a filling material, the vessel being free from electrode. The apparatus includes a center conductive member having a first end and a second end, the center conductive member being characterized by a substantially cylindrical shape centered on a first axis, the first end being coupled to the vessel. The apparatus includes an outer conductive member, the outer conductive member being characterized by a substantially cylindrical shape centered on the first axis, the outer conductive member having an inner volume, the center conductive member being positioned inside the inner volume, the outer conductive member being associated with one or more resonance frequencies. The apparatus includes an input coupling module, the input coupling module comprising a housing and an input coupling element, the housing and the input coupling element being characterized by a substantially cylindrical shape, the input coupling module and the housing sharing a second axis.
According to yet another embodiment, the present invention provides a plasma lamp apparatus. The apparatus includes a vessel being filled with a filling material, the vessel being free from electrode. The apparatus includes a center conductive member having a first end and a second end, the center conductive member being characterized by a substantially cylindrical shape centered on a first axis, the first end being coupled to the vessel. The apparatus includes an outer conductive member having a first portion and a second portion, the first portion being characterized by a substantially cylindrical shape centered on the first axis and a first diameter, the second portion being characterized by the cylindrical shape centered on the first axis and a second diameter, the second diameter being greater than the first diameter, the outer conductive member having an inner volume positioned within the first and second portions of the outer conductive member, the center conductive member being positioned inside the inner volume. The apparatus includes a first ground potential, the first ground potential being electrically coupled to the second end of the center conductive member.
According to yet another embodiment, the present invention provides a plasma lamp apparatus. The apparatus includes a vessel being filled with a filling material, the vessel being free from electrode. The apparatus includes a center conductive member having a first end and a second end, the center conductive member being characterized by a substantially cylindrical shape centered on a first axis, the first end being coupled to the vessel. The apparatus includes an outer conductive member having a first portion and a second portion, the first portion being characterized by a substantially cylindrical shape centered on the first axis and a first diameter, the second portion being characterized by a substantially rectangular shape, the outer conductive member having an inner volume positioned within the first and second portions of the outer conductive member, the center conductive member being positioned inside the inner volume. The apparatus includes a first ground potential, the first ground potential being electrically coupled to the second end of the center conductive member.
According to yet another embodiment, the present invention provides a plasma lamp apparatus. The apparatus includes a vessel being filled with a filling material, the vessel being free from electrode. The apparatus includes a center conductive member having a first end and a second end, the center conductive member being characterized by a substantially cylindrical shape centered on a first axis, the first end being coupled to the vessel. The apparatus includes an outer conductive member having a first portion and a second portion, the first portion being characterized by a substantially cylindrical shape centered on the first axis and a first diameter, the second portion being characterized by a substantially semi-spherical shape, the outer conductive member having an inner volume positioned within the first and second portions of the outer conductive member, the center conductive member being positioned inside the inner volume. The apparatus includes a first ground potential, the first ground potential being electrically coupled to the second end of the center conductive member.
According to yet another embodiment, the present invention provides a plasma lamp apparatus. The apparatus includes a vessel being filled with a filling material, the vessel being free from electrode. The apparatus includes a center conductive member having a first end and a second end, the center conductive member being characterized by a substantially cylindrical shape centered on a first axis, the first end being coupled to the vessel. The apparatus includes an outer conductive member, the outer conductive member being characterized by a substantially cylindrical shape centered on the first axis and a first diameter, the outer conductive member having an inner volume positioned within the outer conductive member, the inner volume having a first portion and a second portion, the inner volume being substantially cylindrical, the center conductive member being positioned inside the first portion of the inner volume. The apparatus includes a first capacitor being positioned with in the second portion of the inner volume, the first capacitor being electrically coupled to the second end of the center conductive member. The apparatus includes a first ground potential, the first ground potential being electrically coupled to the first capacitor.
According to yet another embodiment, the present invention provides a plasma lamp apparatus. The apparatus includes a vessel being filled with a filling material, the vessel being free from electrode. The apparatus includes a center conductive member having a first end and a second end, the center conductive member being characterized by a substantially cylindrical shape centered on a first axis, the first end being coupled to the vessel. The apparatus includes an outer conductive member, the outer conductive member being characterized by a substantially cylindrical shape centered on the first axis and a first diameter, the outer conductive member having an inner volume positioned within the outer conductive member, the inner volume having a first portion and a second portion, the inner volume being substantially cylindrical, the center conductive member being positioned inside the first portion of the inner volume. The apparatus includes an input coupling element including a spiral inductor positioned between the center conductive member and the outer conductive member, the spiral inductor being wrapped around a portion of the center conductive member. The apparatus includes a first ground potential, the first ground potential being electrically coupled to the second end of the center conductive end.
According to yet another embodiment, the present invention provides a plasma lamp apparatus. The apparatus includes a vessel being filled with a filling material, the vessel being free from electrode. The apparatus includes a center conductive member having a first end and a second end, the center conductive member being characterized by a substantially cylindrical shape centered on a first axis, the first end being coupled to the vessel, the center conductive member being characterized by a first length. The apparatus includes an outer conductive member, the outer conductive member being characterized by a substantially cylindrical shape centered on the first axis and a first diameter, the outer conductive member having an inner volume positioned within the outer conductive member, the inner volume having a first portion and a second portion, the inner volume being substantially cylindrical, the inner volume including first portion and a second portion, the center conductive member being positioned inside the first portion of the inner volume. The apparatus includes an input coupling element including a spiral inductor positioned within the second portion of the inner volume, the spiral inductor having an inner portion, the inner portion being free from a solid portion of the center conductive member. The apparatus includes a first ground potential, the first ground potential being electrically coupled to the second end of the center conductive end.
According to yet another embodiment, the present invention provides a plasma lamp apparatus. The apparatus includes a vessel being filled with a filling material, the vessel being free from electrode. The apparatus includes an output coupling member having a first end and a second end, the output coupling member being characterized by a substantially cylindrical shape centered on a first axis, the first end being substantially solid and coupled to the vessel, the second end comprising a first spiral conductor. The apparatus includes an outer conductive member, the outer conductive member being characterized by a substantially cylindrical shape centered on the first axis and a first diameter, the outer conductive member having an inner volume positioned within the outer conductive member, the inner volume having a first portion and a second portion, the inner volume being substantially cylindrical, the output coupling member being positioned inside the of the inner volume. The apparatus includes an input coupling member, the input coupling member including and housing a second spiral inductor positioned within the housing. The apparatus includes a first ground potential, the first ground potential being electrically coupled to the second end of the center conductive end.
According to yet another embodiment, the present invention provides a plasma lamp apparatus. The apparatus includes a vessel being filled with a filling material, the vessel being free from electrode. The apparatus includes an output coupling member having a first end and a second end, the output coupling member being characterized by a substantially cylindrical shape centered on a first axis, the first end being substantially solid and coupled to the vessel, the second end comprising a first spiral conductor. The apparatus includes an outer conductive member, the outer conductive member being characterized by a substantially cylindrical shape centered on the first axis and a first diameter, the outer conductive member having an inner volume positioned within the outer conductive member, the inner volume having a first portion and a second portion, the inner volume being substantially cylindrical, the output coupling member being positioned inside the of the inner volume. The apparatus includes an input coupling member, the input coupling member including and a housing and a second spiral inductor positioned within the housing. The apparatus includes a first capacitor positioned inside the inner volume and electrically coupled to the first spiral conductor. The apparatus includes a first ground potential, the first ground potential being electrically coupled to the first capacitor.
According to yet another embodiment, the present invention provides a plasma lamp apparatus. The apparatus includes a vessel being filled with a filling material, the vessel being free from electrode, the vessel having a top side and a bottom side. The apparatus includes a first output coupling member having a first end and a second end, the first output coupling member being characterized by a substantially cylindrical shape centered on a first axis, the first end being substantially solid and coupled to the bottom side of the vessel, the second end comprising a first spiral conductor. The apparatus includes a second coupling member coupled to the top side of the vessel. The apparatus includes an outer conductive member, the outer conductive member being characterized by a substantially cylindrical shape centered on the first axis and a first diameter, the outer conductive member having an inner volume positioned within the outer conductive member, the inner volume having a first portion and a second portion, the inner volume being substantially cylindrical, the first output coupling member being positioned inside the of the inner volume. The apparatus includes an input coupling member, the input coupling member including and a housing and a second spiral inductor positioned within the housing. The apparatus includes a first capacitor positioned inside the inner volume and electrically coupled to the first spiral conductor. The apparatus includes a first ground potential, the first ground potential being electrically coupled to the first capacitor.
According to yet another embodiment, the present invention provides a plasma lamp apparatus. The apparatus includes a vessel being filled with a filling material, the vessel being free from electrode. The apparatus includes a center conductive member having a first end and a second end, the center conductive member being characterized by a substantially cylindrical shape centered on a first axis, the first end being coupled to the vessel. The apparatus includes an outer conductive member, the outer conductive member being characterized by a substantially cylindrical shape centered on the first axis, the outer conductive member having an inner volume, the center conductive member being positioned inside the inner volume, the outer conductive member being associated with one or more resonance frequencies. The apparatus includes a conductive ring electrically coupled to the vessel. The apparatus includes a grounding strap electrically coupled to the vessel and the conductive ring and the outer conductive member. The apparatus includes a first ground potential, the first ground potential being electrically coupled to the second end of the center conductive member.
According to yet another embodiment, the present invention provides a plasma lamp apparatus. The apparatus includes a vessel being filled with a filling material, the vessel being free from electrode, the vessel having a top side and a bottom side. The apparatus includes a conductive member having a first end and a second end, the center conductive member being characterized by a substantially cylindrical shape centered on a first axis, the first end being coupled to the vessel. The apparatus includes a top coupling member coupled to the top side of the vessel. The apparatus includes an outer conductive member, the outer conductive member being characterized by a substantially cylindrical shape centered on the first axis, the outer conductive member having an inner volume, the center conductive member being positioned inside the inner volume, the outer conductive member being associated with one or more resonance frequencies; a first ground potential, the first ground potential being electrically coupled to the second end of the center conductive member.
One or more benefits may be achieved using the present lamp and related methods. As an example, the present lamp is compact and can be configured inside conventional luminaries, such as luminaries used for street lighting and parking lot lighting. Furthermore, the present lamp can be configured to have an exposed arc to allow use of conventional optical components, such as aluminum reflectors. In one or more embodiments, the present lamp can also be manufactured more efficiently and at lower costs than the conventional dielectric resonators, such as those described in U.S. Pat. No. 6,737,809B2. Furthermore, the lamp can be configured to have an exposed arc to allow use of conventional optical components. These and other benefits may be achieved in one or more embodiments. Further details of the present invention can be found throughout the present specification and more particularly below.
The present invention achieves these benefits and others in the context of known process technology. However, a further understanding of the nature and advantages of the present invention may be realized by reference to the attached drawings.
A more complete understanding of the present invention and its advantages will be gained from a consideration of the following description of preferred embodiments, read in conjunction with the accompanying drawings provided herein. In the figures and description, numerals indicate various features of the invention, and like numerals referring to like features throughout both the drawings and the description.
The present invention is directed to devices and methods for generating light with plasma lamps. More particularly, the present invention provides plasma lamps driven by a radio-frequency source without the use of electrodes inside the bulb and related methods. In a specific embodiment, a coaxial type coupling module is used to drive an electrodeless bulb. Merely by way of example, such plasma lamps can be applied to applications such as stadiums, security, parking lots, military and defense, street lighting, large and small buildings, vehicle headlamps, aircraft landing, bridges, warehouses, UV water treatment, agriculture, architectural lighting, stage lighting, medical illumination, microscopes, projectors and displays, any combination of these, and the like.
The following description is presented to enable one of ordinary skill in the art to make and use the invention and to incorporate it in the context of particular applications. Various modifications, as well as a variety of uses in different applications will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to a wide range of embodiments. Thus, the present invention is not intended to be limited to the embodiments presented, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
In the following detailed description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the present invention may be practiced without necessarily being limited to these specific details. In other instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring the present invention.
The reader's attention is directed to all papers and documents which are filed concurrently with this specification and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference. All the features disclosed in this specification, (including any accompanying claims, abstract, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
Furthermore, any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specific function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C. Section 112, Paragraph 6. In particular, the use of “step of” or “act of” in the Claims herein is not intended to invoke the provisions of 35 U.S.C. 112, Paragraph 6.
Please note, if used, the labels left, right, front, back, top, bottom, forward, reverse, clockwise and counter clockwise have been used for convenience purposes only and are not intended to imply any particular fixed direction. Instead, they are used to reflect relative locations and/or directions between various portions of an object. Additionally, the terms “first” and “second” or other like descriptors do not necessarily imply an order, but should be interpreted using ordinary meaning.
As background for the reader, we would like to describe conventional lamps and their limitations that we discovered. Electrodeless plasma lamps driven by microwave sources have been proposed. Conventional configurations include a gas filled vessel (bulb) containing Argon and a light emitter such as Sulfur or Cesium Bromide (see for example, U.S. Pat. No. 6,476,557B1). The bulb is positioned inside an air resonator/waveguide with the microwave energy provided by a source such as a magnetron and introduced into the resonator/waveguide to heat and ionize the Argon gas and vaporize the Sulfur to emit light. To use RF sources that are efficient and low-cost it is desirable to design the resonator/waveguide to operate at frequencies below approximately 2.5 GHz and preferably below 1 GHz. A conventional air resonator/waveguide operating in the fundamental resonant mode of the resonator at 1 GHz has at least one dimension that is approximately 15 cm long since this length is about half the free-space wavelength (lambda/2) of the resonant frequency of the resonator.
This results in limitations that were discovered. Such limitations include a resonator/waveguide size that is too large for most commercial lighting applications since the resonator/waveguide will not fit within typical lighting fixtures (luminaries). In addition since the bulb was placed inside the air/resonator cavity, the arc of the bulb is not accessible for use in the design of reflectors for various types of luminaries used in commercial and industrial lighting applications.
In the configuration proposed in U.S. Pat. No. 6,737,809B2, Espiau, et al., the air inside the resonator is replaced with alumina resulting in reducing the size of the resonator/waveguide since the free-space wavelength (fundamental mode guided wavelength for this resonator/waveguide) is now reduced approximately by the square-root of the effective dielectric constant of the resonator body. This approach has some advantages over the air resonator in U.S. Pat. No. 6,476,557B1 by reducing the size of the resonator but it has its own drawbacks. Such drawbacks may include higher manufacturing costs, losses associated with the dielectric material, and blockage of light from the bulb by the dielectric material. In this approach, the arc of the bulb is not accessible either limiting its use in various types of luminaries used in commercial and industrial lighting applications.
The other end of the center conductor 115 is connected to ground 201 or the outside (shield) conductor 150 and 151 of the coaxial resonator/waveguide which are also connected to ground potential 200. As shown in
Depending on the application, the filled vessel 130 may include various types of materials. In various embodiments, the filled vessel 130 functions as an electrodeless bulb containing an inert gas such as Argon or Xenon and a light emitter such as Mercury, Sodium, Dysprosium, Sulfur or a metal halide salt such as Indium Bromide, Scandium Bromide, Thallium Iodide, Holmium Bromide, Cesium Iodide or other similar materials (or it can simultaneously contain multiple light emitters).
The vessel 130 includes an arc 115. As shown, the arc 115 inside the bulb is not substantially surrounded by the body of the coaxial resonator/waveguide. The other end of the center conductor of the coaxial resonator/waveguide is connected to ground 201 or the outside conductor (shield) of the coaxial resonator/waveguide 151 which is also connected to ground potential 200. In this case the center conductor is surrounded by air 120.
The resonant frequency of the coaxial resonator/waveguide depends on the dimensions (length, diameter, etc.) of the center conductor as well as the separation between the center conductor and the outside conductor (shield) of the coaxial resonator/waveguide as well as other parameters. The RF impedance match to the gas filled vessel depends on the dimensions of the input coupling element and its separation to the center conductor. In a specific embodiment, the input coupling element and the center conductive are electrically insulated from each other.
It is to be understood that even though the structure of this resonator/waveguide is in the shape of a coaxial resonator/waveguide, the mode of operation of the resonator/waveguide is not necessarily a coaxial mode. For example, there can be other ways for resonator/waveguide to operate.
In certain embodiments, coupling characteristics between the input outputting element 175 and the output coupling element 110 are functions of the dimensions of the coupling elements.
In certain embodiments, coupling characteristics and resonance are also functions of waveguide.
The input coupling element is in the form of spiral inductor 180, which is similar to the inductor illustrated in
Similar to
While the above is a full description of the specific embodiments, various modifications, alternative constructions and equivalents may be used. Therefore, the above description and illustrations should not be taken as limiting the scope of the present invention which is defined by the appended claims.
This application claims priority from U.S. Provisional Patent Application No. 61/391,036, filed Oct. 7, 2010, entitled “ELECTRODELESS LAMPS WITH COAXIAL TYPE RESONATORS/WAVEGUIDES AND GROUNDED COUPLING ELEMENTS,” the disclosure of which is hereby incorporated by reference in its entirety for all purposes.
| Number | Name | Date | Kind |
|---|---|---|---|
| 6476557 | Leng et al. | Nov 2002 | B1 |
| 6737809 | Espiau et al. | May 2004 | B2 |
| 7348732 | Espiau et al. | Mar 2008 | B2 |
| 7719195 | DeVincentis et al. | May 2010 | B2 |
| 8319439 | Hollingsworth et al. | Nov 2012 | B2 |
| Number | Date | Country | |
|---|---|---|---|
| 20120242223 A1 | Sep 2012 | US |
| Number | Date | Country | |
|---|---|---|---|
| 61391036 | Oct 2010 | US |
