High-frequency discharge lamp

Abstract

A high-frequency discharge lamp includes a coaxial waveguide including an internal conductor and a pipe-shaped external conductor surrounding said internal conductor, and a discharge tube including a ceramic or glass tube having an approximately ellipse spherical bulged part formed in a middle of a longitudinal direction, and both ends pinched and sealed; a conductor assembly sealed and attached to an end of the ceramic or glass tube; and an auxiliary electrode for starting disposed near the approximately ellipse spherical bulged part. A rare gas for starting with 1 atmospheric pressure or more at room temperature together with a light emission substance is enclosed inside of the approximately ellipse spherical bulged part. The discharge tube is inserted conductor assembly end first and held in a top opening of the coaxial waveguide. A high-voltage pulse generated by a high-voltage pulse generator is applied to the auxiliary electrode through a pulse transmission line.

Description

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a longitudinal sectional view showing an outline of a discharge lamp which is a first embodiment of the invention.

FIG. 1( a) is an enlarged perspective view of discharge tube fixing and holding means which is a main part of the same discharge lamp.

FIG. 2( a) is a diagram showing a configuration of a high-voltage pulse generator, and FIG. 2(b) is a diagram showing a pulse generated by the same high-voltage pulse generator.

FIG. 3 is views explaining the first half of a manufacturing process of a discharge tube, and 3(a) and 3(b) are views showing a process of molding an ellipse spherical bulged part, and 3(c) and 3(d) are views showing a primary pinch seal process, and 3(e) is a sectional view of a glass tube through the primary pinch seal process.

FIG. 4 is views explaining the second half of the manufacturing process of the discharge tube, and 4(a) is a view showing a pellet supply process, and 4(b) and 4(c) are views showing a conductor assembly insertion process, and 4(d) is a view showing a glass tube temporary seal process, and 4(e) is a view showing a secondary pinch seal process.

FIG. 5 is views explaining a shroud tube welding process, and 5(a) is a sectional view of the discharge tube before welding of the shroud tube, and 5(b) and 5(c) are views showing the shroud tube welding process.

FIGS. 6( a) to 6(f) are diagrams respectively showing modified examples (other specifications) of the discharge tube which is a main part of the discharge lamp which is the first embodiment of the invention.

FIG. 7 is an explanatory view explaining a process of covering a conductor bar protruding to discharge space with a cap part.

FIG. 8 is a diagram showing a modified example of an auxiliary electrode for starting which is a main part of the discharge lamp which is the first embodiment of the invention.

FIG. 9 is a longitudinal sectional view showing an outline of a discharge lamp which is a second embodiment of the invention.

FIG. 10 is a longitudinal sectional view showing a modified example of an internal conductor constructing a waveguide of the same discharge lamp.

FIG. 11 (a) is a longitudinal sectional view showing an outline of a discharge lamp which is a third embodiment of the invention, and FIG. 11 (b) is a longitudinal sectional view showing an outline of a discharge lamp which is a fourth embodiment of the invention.

FIG. 12 is a longitudinal sectional view of a main part of a discharge lamp which is a fifth embodiment of the invention.

FIG. 13 is a longitudinal sectional view of a discharge tube which is a main part of a discharge lamp which is a sixth embodiment of the invention.

FIG. 14 is the whole configuration diagram of a conventional discharge lamp.

FIG. 15 is a longitudinal sectional view of a discharge tube which is a main part of the same discharge lamp.

Claims

1. A high-frequency discharge lamp comprising a coaxial waveguide for high-frequency electromagnetic wave transmissionwherein the coaxial waveguide comprises an internal conductor anda pipe-shaped external conductor surrounding said internal conductor, and a discharge tube for emitting light of discharge by plasma generated by electromagnetic waves,wherein the discharge tube is attached to the top of the waveguide, andis constructed in a double end shape in which both ends of a ceramic tube or a glass tube are pinched and sealed,wherein the ceramic tube or the glass tube comprises an approximately ellipse spherical bulged part formed in a middle of a longitudinal direction,wherein a conductor assembly is sealed and attached to at least a proximal side seal attachment part,wherein a rare gas for starting with 1 atmospheric pressure or more at room temperature together with a light emission substance is enclosed inside of the approximately ellipse spherical bulged part,wherein an electromagnetic wave irradiation part is constructed by the conductor assembly and the external conductor top of the coaxial waveguide surrounding said conductor assembly by inserting and holding the proximal side seal attachment part of the discharge tube in a top opening of the coaxial waveguide so that the conductor assembly approaches the internal conductor of the waveguide, andwherein an auxiliary electrode for starting to which a high-voltage pulse generated by a high-voltage pulse generator is applied through a pulse transmission line is disposed near the approximately ellipse spherical bulged part of the discharge tube.

2. The high-frequency discharge lamp as claimed in claim 1, wherein the auxiliary electrode for starting is constructed by a conductor assembly sealed and attached to a distal side seal attachment part of the discharge tube.

3. The high-frequency discharge lamp as claimed in claim 1, wherein the auxiliary electrode for starting is constructed by a conductor assembly sealed and attached to a proximal side seal attachment part of the discharge tube.

4. The high-frequency discharge lamp as in claim 1, wherein the approximately ellipse spherical bulged part is covered with hermetically sealed space defined by a cylindrical shroud for ultraviolet shielding integrally welded to the seal attachment part.

5. The high-frequency discharge lamp as in claim 4, wherein a gas capable of assisting discharge, the gas with less than 1 atmospheric pressure at room temperature, is enclosed inside of the hermetically sealed space surrounding the approximately ellipse spherical bulged part defined by the shroud.

6. The high-frequency discharge lamp as in claim 1, wherein the discharge tube is constructed of a quartz glass tube and the seal attachment part is constructed of a pinch seal part and a part of the conductor assembly sealed and attached to at least the proximal side pinch seal part among a pair of the pinch seal parts protrudes to the inside of the approximately ellipse spherical bulged part.

7. The high-frequency discharge lamp as claimed in claim 2, wherein the auxiliary electrode for starting is constructed by a conductor assembly sealed and attached to a proximal side seal attachment part of the discharge tube.

8. The high-frequency discharge lamp as in claim 2, wherein the approximately ellipse spherical bulged part is covered with hermetically sealed space defined by a cylindrical shroud for ultraviolet shielding integrally welded to the seal attachment part.

9. The high-frequency discharge lamp as in claim 3, wherein the approximately ellipse spherical bulged part is covered with hermetically sealed space defined by a cylindrical shroud for ultraviolet shielding integrally welded to the seal attachment part.

10. A high-frequency discharge lamp comprising: a coaxial waveguide comprising an internal conductor and a pipe-shaped external conductor surrounding said internal conductor, anda discharge tube comprising: a ceramic or glass tube having: an approximately ellipse spherical bulged part formed in a middle of a longitudinal direction, andboth ends pinched and sealed;a conductor assembly sealed and attached to an end of the ceramic or glass tube; andan auxiliary electrode for -starting disposed near the approximately ellipse spherical bulged part,wherein a rare gas for starting with 1 atmospheric pressure or more at room temperature together with a light emission substance is enclosed inside of the approximately ellipse spherical bulged part,wherein the discharge tube is inserted conductor assembly end first and held in a top opening of the coaxial waveguide, andwherein a high-voltage pulse generated by a high-voltage pulse generator is applied to the auxiliary electrode through a pulse transmission line.

11. The high-frequency discharge lamp as claimed in claim 10, wherein the auxiliary electrode for starting comprises a second conductor assembly sealed and attached to the other end of the ceramic or glass tube.

12. The high-frequency discharge lamp as claimed in claim 10, wherein the auxiliary electrode for starting is disposed on the end where the conductor assembly is sealed and attached.

13. The high-frequency discharge lamp as in claim 10, wherein the approximately ellipse spherical bulged part is covered with hermetically sealed space defined by a cylindrical shroud for ultraviolet shielding.

14. The high-frequency discharge lamp as in claim 10, wherein the discharge tube is constructed of a quartz glass tube and a part of the conductor assembly sealed and attached protrudes to inside of the approximately ellipse spherical bulged part.

15. A method of manufacturing a high-frequency discharge lamp comprising a coaxial waveguide and a discharge tube, the method comprising: constructing the discharge tube by forming an approximately ellipse spherical bulged part in a middle of a longitudinal direction of a ceramic or glass tube,enclosing a rare gas for starting with 1 atmospheric pressure or more at room temperature together with a light emission substance inside of the approximately ellipse spherical bulged part,pinching and sealing both ends of the ceramic or glass tube,sealing and attaching a conductor assembly to an end of the ceramic or glass tube, anddisposing an auxiliary electrode for starting near the approximately ellipse spherical bulged part;constructing the coaxial waveguide with an internal conductor and a pipe-shaped external conductor surrounding said internal conductor;adapting the coaxial waveguide to hold the discharge tube in a top opening thereof; andinserting the discharge tube conductor assembly end first into the top opening of the coaxial waveguide.

16. The method of manufacturing a high-frequency discharge lamp as claimed in claim 15, wherein the starting auxiliary electrode is constructed by sealing and attaching a second conductor assembly to the other end of the ceramic or glass tube.

17. The method of manufacturing a high-frequency discharge lamp as claimed in claim 15, wherein the auxiliary electrode for starting is constructed by the sealing and attaching of the conductor assembly to the end of the ceramic or glass tube.

18. The method of manufacturing a high-frequency discharge lamp as in claim 15, further comprising covering the ellipse spherical bulged part with hermetically sealed space defined by a cylindrical shroud for ultraviolet shielding.

19. The method of manufacturing a high-frequency discharge lamp as in claim 15, wherein the discharge tube is constructed of a quartz glass tube and a part of the conductor assembly sealed and attached protrudes to inside of the approximately ellipse spherical bulged part.