Electrodeless discharge lamp system

• US 20020047615A1
• Filed: 09/25/2001
• Published: 04/25/2002
• Est. Priority Date: 09/26/2000
• Status: Active Grant

• Current Assignee: Toshiba Lighting & Technology Corporation (Toshiba Corporation)
• Original Assignee: Toshiba Lighting & Technology Corporation (Toshiba Corporation)
• Inventors: Doi, Hiroyuki, Terai, Takashi, Kawamura, Masaaki, Yokozeki, Ichiro, Suzuki, Ioshiya
• Granted Patent: US 6,700,332 B2
• Time in Patent Office: Days
• US Class Current: 315/248
• CPC Class Codes: H05B 41/24 in which the lamp is fed by high frequency ac, or with separate oscillator frequencyH05B41/26 takes precedence
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

An electrodeless discharge lamp system includes an excitation coil placed in proximity of the electrodeless discharge lamp, a resonance circuit for supplying appropriate power to the excitation coil, and a high frequency power source driver and wherein, the combined output is achieved by operating the parallel connected power sources in synchronization or approximately in synchronization with each other.

Claims

1. An electrodeless discharge lamp system comprising:

an electrodeless discharge lamp;

an excitation coil placed in proximity of the electrodeless discharge lamp;

a resonance circuit for supplying appropriate power to the excitation coil; and

a high frequency power source driver,

wherein a combined output is achieved by operating the parallel-connected power sources in synchronization or almost in synchronization with each other.

2. An electrodeless discharge lamp system as claimed in claim 1, further comprising a DC voltage superposing circuit for superposing a DC voltage to the output of the driver.

3. An electrodeless discharge lamp system as claimed in claim 2, wherein the DC voltage is adjustable in the DC voltage superposing circuit.

4. An electrodeless discharge lamp system claimed in any one of claims 2 and 3, wherein the DC voltage superposing circuit generates a mean voltage by executing a half-wave rectification on the output of the high frequency power source.

5. An electrodeless discharge lamp system comprising:

an electrodeless discharge lamp;

an excitation coil which is placed in proximity of the electrodeless discharge lamp;

a matching circuit for preparing conditions of the excitation coil for exciting the electrodeless discharge lamp;

multiple DC-RF power converters connected in parallel to operate in synchronization or almost in synchronization with each other;

a combiner for combining outputs of the parallel-connected power converters; and

a transmission line for transmitting the power from the combiner to the matching circuit.

6. An electrodeless discharge lamp system as claimed in claim 5, wherein a combined output impedance (Zamp-out) of N-pieces of parallel-connected DC-RF power converters to a characteristic impedance (Ztl) of the transmission line is defined by the following equation.

Zamp-out=N·

Ztl

7. An electrodeless discharge lamp system, comprising:

multiple electrodeless discharge lamp units having multiple electrodeless discharge lamp, excitation coils placed in proximity of these electrodeless discharge lamp, and a matching circuit for supplying an appropriate power to each excitation coil;

high frequency power sources, which is supplied an external reference clock signal and amplifies the reference clock signal for supplying resulted high frequency power to the electrodeless discharge lamp units via coaxial cables; and

a reference clock generator connected to each of the high frequency power sources for parallel supplying only one reference clock signal to the high frequency power sources via coaxial cables,

wherein the lengths of the coaxial cables connecting the reference clock generator and the high frequency power sources roughly agree with each other.

8. An electrodeless discharge lamp system, comprising:

multiple electrodeless discharge lamp units having multiple electrodeless discharge lamp, excitation coils placed in proximity of these electrodeless discharge lamp, and a matching circuit for supplying an appropriate power to each excitation coil;

high frequency power sources, which is supplied an external reference clock signal and amplifies the reference clock signal for supplying resulted high frequency power to the electrodeless discharge lamp unit via coaxial cables; and

a reference clock generator connected in a cascaded manner to each of the high frequency power sources for supplying only one reference clock signal to the high frequency power sources via coaxial cables,

wherein the length of the coaxial cables connected to the high frequency power sources roughly agree with each other so as to make the phase of the reference clock and the phases of the outputs of the high frequency power sources with each other.

9. An electrodeless discharge lamp system, comprising:

a bactericidal device provided with multiple electrodeless discharge lamps, excitation coils placed in proximity of these electrodeless discharge lamps, matching circuits for supplying appropriate powers to the excitation coils, and a bactericidal tank accommodating therein multiple electrodeless discharge lamp units;

high frequency power sources for supplying high frequency powers to the electrodeless discharge lamp units; and

DC power sources for supplying DC voltages to the high frequency power sources,

wherein the DC voltages are determined as a single unit by applying only one external dimming signal to each DC power sources.

10. An electrodeless discharge lamp system as claimed in claim 9, wherein feedback signals for determining the DC voltages based on the amount the power detectable in the electrodeless discharge lamp system itself, and then the DC voltages are determined as a single unit.

11. An electrodeless discharge lamp system, comprising:

an electrodeless discharge lamp;

an excitation coil for supplying a high frequency power to the electrodeless discharge lamp;

a high frequency power source for generating the high frequency power;

a high frequency power source driver; and

;

an output circuit for outputting the high frequency power of the high frequency power source to the excitation coils.

wherein the high frequency power source is provided with a main amplifier, a preamplifier for driving the main amplifier and a coaxial cable for coupling the main amplifier and the preamplifier.

12. An electrodeless discharge lamp system as claimed in claim 11, wherein the high frequency power source is provided with a distributor for a block of multiple main amplifiers, and the preamplifier is connected to the distributor via a coaxial cable.

13. An electrodeless discharge lamp system as claimed in claim 11, wherein the high frequency power source is provided with a distributor for a block of multiple preamplifiers, and the distributor is connected to multiple main amplifiers via coaxial cables.

15. An electrodeless discharge lamp system as claimed in claim 14, further comprising:

a distributor provided with a balance resistor for distributing the parallel inputs to the power converters,

wherein when the output terminal of either one of the power conversion circuits is opened, short-circuited or no signal input, the rated power of the balance resistor in the distributor is set to a value that the output terminal of other power converters can not stand.

16. An electrodeless discharge lamp system as claimed in claim 15, wherein tho distributor and the combiner are arranged on the extension of or equidistantly from the parallel-connected power converters.

14. An electrodeless discharge lamp system, comprising:

an electrodeless discharge lamp;

an excitation coil for supplying a high frequency power to the electrodeless discharge lamp;

a high frequency power source provided with multiple parallel-connected power converters for generating the high frequency power;

a high frequency power source driver;

an output circuit for outputting the high frequency power of the high frequency power source to the excitation coil; and

a combiner provided with a balance resistor for combining the parallel outputs from the power converters,

wherein when the output terminal of either one of the power conversion circuits is opened, short-circuited or no signal input, the rated power of the balance resistor in the combiner is set to a value that the output terminal of other power converters can not stand.

17. An electrodeless discharge lamp system, comprising:

an electrodeless discharge lamp;

an excitation coil for supplying a high frequency power to the electrodeless discharge lamp;

a high frequency power source provided with multiple parallel-connected power converters for generating the high frequency power;

a high frequency power source drive;

an output circuit for outputting the high frequency power of the high frequency power source to the excitation coils

multiple stages of combiners for combining the parallel outputs from the power converters; and

an impedance converter provided with a λ

/4 transmission line for converting the impedance of the combined power into a characteristic impedance of a transmission cable to the electrodeless discharge lamp.

18. An electrodeless discharge lamp system, comprising;

an electrodeless discharge lamp;

an excitation coil for supplying a high frequency power to the electrodeless discharge lamp;

a high frequency power source provided with multiple parallel-connected power converters for generating the high frequency power;

a high frequency power source driver; and

an output circuit for outputting the high frequency power of the high frequency power source to the excitation coil,

wherein each of the power converters is provided with an FET and a series LC resonance filter for a class-E operation, and

wherein respective FETs are arranged in parallel with each other, and the coils constituting the inductor of the series LC resonance filter are arranged in parallel with each other, and in a slanting position against the corresponding FETS.

19. An electrodeless discharge lamp system characterized by that,

an electrodeless discharge lamp;

an excitation coil for supplying a high frequency power to the electrodeless discharge lamp;

a high frequency power source for generating the high frequency power;

a high frequency power source driver; and

;

power;

an output circuit for outputting the high frequency power of the high frequency power source to the excitation coils,

wherein it is configured that the phase angle of the output of the high frequency power source in detected, and the frequency of the high frequency power source is varied in response to the detected phase angle of the output of the high frequency power source, and

wherein it is configured that the power source voltage of the high frequency power source is detected, and the power source voltage is varied in response to the detected power of the high frequency power source.