Lamp-to-light guide coupling arrangement for an electrodeless high intensity discharge lamp

• US 5,675,677 A
• Filed: 05/26/1995
• Issued: 10/07/1997
• Est. Priority Date: 12/10/1993
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: King, Kenneth S., Cassarly, William J., Davenport, John M., Allen, Gary R., Ahlgren, Frederic F., Dakin, James T., Hansler, Richard L., Parham, Thomas G., Duffy, Mark E.
• Primary Examiner(s): Palmer, Phan T. H.
• Application Number:
  US08/451,625
• Time in Patent Office: 865 Days
• Field of Search: 385/31, 385/32, 385/33, 385/36, 385/39, 385/74, 385/146, 385/901, 315/248, 315/34, 315/39, 315/344, 362/32, 362/307, 362/261, 362/262, 362/347
• US Class Current: 385/31
• CPC Class Codes: G02B 6/40 having fibre bundle mating means
• CPC Class Codes: G02B 6/4296 coupling with sources of high radiant energy, e.g. high power lasers, high temperature light sources
• CPC Class Codes: G02B 6/4298 coupling with non-coherent light sources and/or radiation detectors, e.g. lamps, incandescent bulbs, scintillation chambers
• CPC Class Codes: Y10S 385/901 Illuminating or display apparatus

Abstract

A lamp-to-light guide coupling arrangement includes an electrodeless high intensity discharge lamp comprising an arc tube with an ionizable fill, and an excitation circuit for electrically exciting the ionizable fill to induce therein a light-producing arc discharge. The coupling arrangement further includes a coupling device comprising a generally tubular, hollow body that has an inlet end for receiving light from the arc discharge and a larger, outlet end. The coupling device further comprises an interiorly directed reflector on a surface of the hollow body for reflecting visible light. Such coupling device is shaped so as to receive light at one solid angle over an area of the inlet end and to transmit light at a smaller solid angle but over a larger area of the outlet end. The coupling device is preferably formed from dielectric material. The reflector preferably comprises a refractory optical interference filter.

Claims

1. A lamp-to-light guide coupling arrangement for an electrodeless discharge lamp having an arc tube containing an ionizable fill which is excitable so as to produce a light generating arc discharge and has associated therewith, certain thermal and electrical operating properties, said coupling arrangement comprising:

(a) a coupling device disposed in close proximity to said discharge lamp and being of a generally tubular, hollow construction having an inlet end for receiving light from said arc discharge and a larger, output end, said inlet end having an area which is substantially the same as a cross sectional area of said discharge lamp and said larger output end having a diameter which is approximately 2 to 3 times the diameter of said discharge lamp;

(b) reflector means disposed on at least a portion of a surface of said hollow coupling device and being effective for reflecting light interiorly of said coupling device;

(c) wherein said coupling device is shaped so as to receive light at one solid angle over an area of said inlet end and to transmit light through said outlet end at a smaller angle but over a larger area of said outlet end;

(d) at least one light guide coupled to said outlet end of said coupling device; and

,

(e) wherein said coupling device with said reflector means being disposed thereon, is effective so that, when in such close proximity to said discharge lamp, the thermal and operating properties of said discharge lamp remain substantially unaffected by said coupling device.

2. The lamp-to-light guide arrangement of claim 1, wherein said coupling device is formed from dielectric material.

3. The lamp-to-light guide coupling arrangement of claim 1, wherein said coupling device is shaped so as to define a compound parabolic concentrator.

4. The lamp-to-light guide coupling arrangement of claim 1, wherein said at least one light guide is disposed within said outlet end of said coupling device.

5. The lamp-to-light guide coupling arrangement of claim 1, wherein said reflector means includes electrically non-conductive an optical interference filter transmissive of a substantial portion of the spectrum of infrared light, so as to allow heat from said lamp to escape through said coupling device.

6. The lamp-to-light guide coupling arrangement of claim 1, in combination with an electrically conductive enclosure for enclosing said lamp-to-light guide coupling arrangement, whereby electromagnetic interference resulting from operation of said lamp is substantially confined to within said enclosure.

7. The lamp-to-light guide coupling arrangement of claim 1, further comprising a reflecting member positioned within said coupling device between said lamp and said at least one light guide, for returning towards said lamp, radiation comprising at least one of infrared and ultraviolet radiation.

8. The lamp-to-light guide coupling arrangement of claim 1, wherein a light-transmitting side of said arc tube of said lamp is received within said inlet end of said hollow coupling device.

9. The lamp-to-light guide coupling arrangement of claim 8, wherein said light transmitting side of said arc tube comprises a flat surface.

10. The lamp-to-light guide coupling arrangement of claim 1, further comprising an intermediate, light-transmissive refractory rod positioned between said arc tube of said lamp and said hollow coupling device, being effective so as to thermally isolate said at least one light guide from said lamp.

11. The lamp-to-light guide coupling arrangement of claim 1, further comprising a mirror member receptive of light from said arc discharge through a first surface of said arc tube, and effective so as to reflect such light back through said one side and towards another surface of said arc tube.

12. A light distribution arrangement for transmitting light output from an electrodeless high intensity discharge lamp to at least one remote location, said light distribution arrangement comprising:

(a) said electrodeless high intensity discharge lamp including an arc tube with an ionizable fill;

(b) an excitation coil surrounding said arc tube for electromagnetically exciting said ionizable fill to induce therein a light-producing arc discharge;

(c) a coupling device comprising;

(i) a generally tubular body having an inlet end for receiving light from said arc discharge and a larger, outlet end;

(ii) wherein said coupling device is solid in construction and has total internal reflectance properties associated therewith, said total internal reflectance properties being achieved without the use of an electrically conducting material;

(iii) said coupling device being shaped so as to receive light at one solid angle over an area of said inlet end and to transmit light at a smaller solid angle but over a larger area of said outlet end; and

(d) at least one light guide coupled to said outlet end of said coupling device.

13. The light distribution arrangement of claim 12, wherein said coupling device is formed from dielectric material.

14. The light distribution arrangement of claim 12, wherein said coupling device is shaped so as to define a compound parabolic concentrator.

15. The light distribution arrangement of claim 12, further comprising an intermediate, light-transmissive refractory rod positioned between said arc tube of said lamp and said coupling device so as to further thermally isolate said at least one light guide from said lamp.

16. The light distribution arrangement of claim 15, wherein said light transmitting side of said arc tube comprises a flat surface spaced in close proximity to an end of said refractory rod.