Plasma emission device, and electromagnetic wave generator used therein

Patent metadata

Field	Value
Publication number	US-9648718-B2
Application number	US-201514592188-A
Country	US
Kind code	B2
Filing date	Jan 8, 2015
Priority date	Jul 9, 2012
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

A plasma emission device in an embodiment includes: an electromagnetic wave generator; a waveguide transmitting an electromagnetic wave emitted from the electromagnetic wave generator, an antenna receiving the electromagnetic wave transmitted through the waveguide; an electromagnetic wave focuser which is irradiated with the electromagnetic wave from the antenna; and an electrodeless bulb disposed in the electromagnetic wave focuser. A light-emitting material filled in the electrodeless bulb is excited by the electromagnetic wave focused by the electromagnetic wave focuser to perform plasma emission. The electromagnetic wave generator includes a cathode part and an anode part. A maximum output efficiency of the electromagnetic wave to be generated with an input power of 700 W or less is 70% or more.

First claim

What is claimed is:

1. A plasma emission device, comprising:
an electromagnetic wave generator;
a power source unit supplying power to the electromagnetic wave generator;
a waveguide transmitting an electromagnetic wave emitted from the electromagnetic wave generator;
an antenna receiving the electromagnetic wave transmitted through the waveguide;
an electromagnetic wave focuser which is irradiated with the electromagnetic wave from the antenna; and
a light emitting unit having an electrodeless bulb disposed in the electromagnetic wave focuser and filled with a light-emitting material therein, the electrodeless bulb plasma-emitting by the electromagnetic wave being focused by the electromagnetic wave focuser to excite the light-emitting material,
wherein the electromagnetic wave generator comprises a cathode part and an anode part surrounding the cathode part, and a maximum output efficiency of the electromagnetic wave to be generated with an input power of 700 W or less in the electromagnetic wave generator is 70% or more, and
wherein the electromagnetic wave generator generates the electromagnetic wave in an anode current region of 200 mA or less with respect to the input power, and a maximum output efficiency of the electromagnetic wave in the anode current region is 70% or more.

2. The plasma emission device according to claim 1 ,
wherein a fluctuation rate of an output efficiency of the electromagnetic wave to be generated with an input power of from 150 to 700 W in the electromagnetic wave generator is 15% or less.

3. The plasma emission device according to claim 1 ,
wherein a fluctuation rate of an output efficiency of the electromagnetic wave to be generated in an anode current region of from 50 to 200 mA in the electromagnetic wave generator is 15% or less.

4. The plasma emission device according to claim 1 ,
wherein the electromagnetic wave generator comprises:
the anode part having an anode cylinder, and 12 or more anode resonant plates radially arranged from an inner wall of the anode cylinder toward a tube axis thereof;
the cathode part having a filament disposed along the tube axis of the anode cylinder; and
an excitation circuit generating a magnetic field in the tube axis direction of the anode cylinder.

5. The plasma emission device according to claim 4 ,
wherein the excitation circuit includes a permanent magnet having a magnetic flux density of 230 mT or more.

6. The plasma emission device according to claim 1 ,
wherein an output efficiency of the electromagnetic wave to be generated in a whole region of an input power of from 100 to 350 W in the electromagnetic wave generator is 72% or more.

7. The plasma emission device according to claim 6 ,
wherein the electromagnetic wave generator generates the electromagnetic wave in an anode current region of from 30 to 150 mA with respect to the input power, and the electromagnetic wave exhibits a maximum output efficiency with an input power of from 250 to 350 W.

8. The plasma emission device according to claim 1 ,
wherein an output efficiency of the electromagnetic wave to be generated in a whole region of an input power of from 100 to 500 W in the electromagnetic wave generator is 72% or more.

9. The plasma emission device according to claim 8 ,
wherein the electromagnetic wave generator generates the electromagnetic wave in an anode current region of from 30 to 200 mA with respect to the input power, and the electromagnetic wave exhibits a maximum output efficiency with an input power of from 200 to 300 W.

10. The plasma emission device according to claim 1 ,
wherein the electromagnetic wave focuser comprises a focuser main body made of a high dielectric material, and the electrodeless bulb is installed in the focuser main body.

11. An electromagnetic wave generator for supplying an electromagnetic wave to a plasma emission device having an electrodeless bulb, comprising:
an anode part having an anode cylinder, and 12 or more anode resonant plates radially arranged from an inner wall of the anode cylinder toward a tube axis thereof;
a cathode part having a filament disposed along the tube axis of the anode cylinder; and
an excitation circuit generating a magnetic field in the tube axis direction of the anode cylinder,
wherein a maximum output efficiency of the electromagnetic wave to be generated with an input power of 700 W or less is 70% or more, and
wherein the electromagnetic wave is generated in an anode current region of 200 mA or less with respect to the input power.

12. The electromagnetic wave generator according to claim 11 ,
wherein a fluctuation range of an output efficiency of the electromagnetic wave to be generated with an input power of from 150 to 700 W is 15% or less.

13. The electromagnetic wave generator according to claim 11 ,
wherein the excitation circuit includes a permanent magnet having a magnetic flux density of 230 mT or more.

14. The plasma emission device according to claim 4 ,
wherein a ratio (rc/ra) of a radius (rc) of a cathode outside diameter (2 rc) to a radius (ra) of an anode inside diameter (2 ra) is 0.487 or more, wherein the anode inside diameter (2 ra) is an inside diameter of inner end portions of the anode resonant plates.

15. The electromagnetic wave generator according to claim 11 ,
wherein a ratio (rc/ra) of a radius (rc) of a cathode outside diameter (2 rc) to a radius (ra) of an anode inside diameter (2 ra) is 0.487 or more, wherein the anode inside diameter (2 ra) is an inside diameter of inner end portions of the anode resonant plates.

Assignees

• Toshiba Hokuto Electronics Corp

Inventors

• Kato Naoya

Classifications

• H01J65/044 Primary

  the field being produced by a separate microwave unit · CPC title

• H05H1/46 Primary

  using applied electromagnetic fields, e.g. high frequency or microwave energy (H05H1/26 takes precedence) · CPC title