Claims
- 1. A microwave generated plasma light source apparatus comprising: a microwave generator; a microwave cavity having a light reflecting member forming at least a portion of said cavity, said microwave generator being coupled through a feeding opening in said cavity to said cavity; a member transparent to light and opaque to microwaves disposed across an opening of said cavity opposite said feeding opening; a waveguide for guiding microwaves generated by said microwave generator to said feeding opening of said cavity; and an electrodeless discharge bulb disposed at a position in said cavity such that said cavity operates as a resonant cavity at least when said bulb is emitting light, said bulb encapsulating at least one discharge light emissive substance and having a shape and being sufficiently small that said bulb functions substantially as a point light source, said bulb being made of transparent quartz glass and having an inner diameter such that a ratio of an outer surface area of said bulb to the microwave input power is from 1.5 mm.sup.2 /W to 15 mm.sup.2 /W, the weight of said bulb with respect to the microwave input power being no more than 3.0.times.10.sup.-2 g/W, said microwave generator comprising means for generating microwaves intermittently with a rest interval of no more than 5 msec.
- 2. The microwave generated plasma light source apparatus as claimed in claim 1 wherein said light reflecting member comprises a light reflecting shell having rotational symmetry.
- 3. The microwave generated plasma light source apparatus as claimed in claim 1 wherein said light reflecting member comprises a center reflecting shell having at least a portion thereof of the same shape as said bulb and having a wing portion extending from a peripheral edge of said center reflecting shell, an inner surface of said wing portion being non-reflective to light.
- 4. The microwave generated plasma light source apparatus as claimed in claim 1 further comprising lens means for one of collecting and scattering light passing through said member transparent to light and opaque to microwaves.
- 5. The microwave generated plasma light source apparatus as claimed in claim 1 wherein said non-electrode discharge bulb comprises an electrically conductive discharge start assisting member disposed at least in the vicinity of said bulb for concentrating a magnetic field.
- 6. The microwave generated plasma light source apparatus as claimed in claim 5 wherein said electrically conductive discharge start assisting member is encapsulated in said bulb.
- 7. The microwave generated plasma light source apparatus as claimed in claim 5 wherein said discharge start assisting member is disposed on a side of said bulb facing said feeding opening.
- 8. The microwave generated plasma light source apparatus as claimed in claim 5 wherein said discharge start assisting member is in the shape of wire.
- 9. The microwave generated plasma light source apparatus as claimed in claim 5 wherein said start assisting member comprises an electrically conductive member and a dielectric cover covering said electrically conductive member.
- 10. The microwave generated plasma light source apparatus as claimed in claim 9 wherein a space is provided between said conductive member and said dielectric cover, said space being at a reduced pressure.
- 11. The microwave generated plasma light source apparatus as claimed in claim 1 wherein said light reflecting member is formed with a pair of opposed cut-off sleeves into which a pair of supporting members of said bulb are inserted to support said bulb.
- 12. The microwave generated plasma light source apparatus as claimed in claim 11 wherein said bulb has said supporting members integrally formed therewith.
- 13. The microwave generated plasma light source apparatus as claimd in claim 1 wherein said discharge light emissive substance encapsulated in said bulb comprises mercury of 7.times.10.sup.-6 gram atom/cc to 60.times.10.sup.-6 gram atom/cc, gallium of at least 1.times.10.sup.-7 gram atom/cc and halogen of 1.5.times.10.sup.-7 to 50.times.10.sup.-7 gram atom/cc.
- 14. The microwave generated plasma light source apparatus as claimed in claim 1 wherein said microwave generator comprises a magnetron and full-wave voltage doubler power supply means for driving said magnetron.
- 15. The microwave generated plasma light source apparatus as claimed in claim 1 wherein the length of said waveguide is selected such that the operation of said magnetron is within a phase width of a quarter wavelength with respect to a sink region immediately after said bulb is ignited.
Priority Claims (1)
Number |
Date |
Country |
Kind |
55-29911 |
Mar 1980 |
JPX |
|
Parent Case Info
This application is a continuation of application Ser. No. 242,075, filed 3/9/81, now abandoned.
US Referenced Citations (9)
Foreign Referenced Citations (1)
Number |
Date |
Country |
54-82876 |
Jul 1979 |
JPX |
Continuations (1)
|
Number |
Date |
Country |
Parent |
242075 |
Mar 1981 |
|