Curing apparatus employing angled UVLEDs

Patent metadata

Field	Value
Publication number	US-9687875-B2
Application number	US-201514886494-A
Country	US
Kind code	B2
Filing date	Oct 19, 2015
Priority date	May 20, 2010
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

A UVLED apparatus (and related system and method) provide efficient curing of an optical-fiber coating on a drawn glass fiber. The apparatus employs one or more UVLEDs that emit electromagnetic radiation into a curing space. An incompletely cured optical-fiber coating, which is formed upon a glass fiber, absorbs emitted and reflected electromagnetic radiation to promote efficient curing.

First claim

The invention claimed is:

1. An apparatus for curing a coated glass fiber, comprising:
a substantially closed, substantially cylindrical cavity having a substantially elliptical cross-section and a reflective inner surface, said cavity defining a first line focus, a second line focus, and a major axis intersecting the first line focus and the second line focus, the second line focus defining a curing axis;
a protective tube that is substantially transparent to ultraviolet (UV) radiation, said protective tube surrounding the curing axis; and
an ultraviolet light emitting diode (UVLED) source positioned within said cavity at the first line focus, wherein said UVLED source is configured to have (i) a substantially Lambertian emission pattern that defines a line of average emission Lavg and (ii) an emission angle a between the major axis and Lavg defined by the following equation:
α≧θ source /2+arctan( r tube /(2 f )),

where
r tube is the radius of the protective tube,
2f is the distance between the first line focus and the second line focus, and
θ source is the angle of the emittance cone of the UVLED source that contains 95 percent of the emitted power from the UVLED source.

2. The apparatus according to claim 1 , wherein said cavity has an elliptical cross-section.

3. The apparatus according to claim 1 , wherein said protective tube is a quartz tube.

4. The apparatus according to claim 1 , wherein said UVLED source is a single UVLED.

5. The apparatus according to claim 1 , wherein said UVLED source comprises of a plurality of UVLEDs.

6. The apparatus according to claim 5 , wherein said plurality of UVLEDs comprises at least two UVLEDs that emit electromagnetic radiation at different output intensities.

7. The apparatus according to claim 1 , comprising a plurality of UVLED sources positioned within said cavity.

8. The apparatus according to claim 7 , wherein said plurality of UVLEDs sources comprises at least two UVLED sources that emit electromagnetic radiation at different output intensities.

9. The apparatus according to claim 1 , wherein at least 90 percent of the electromagnetic radiation emitted by said UVLED source has wavelengths of between about 250 nanometers and 400 nanometers.

10. The apparatus according to claim 1 , wherein at least 80 percent of the electromagnetic radiation emitted by said UVLED source has wavelengths of between about 300 nanometers and 450 nanometers.

11. The apparatus according to claim 1 , wherein at least 80 percent of the electromagnetic radiation emitted by said UVLED source has wavelengths of between about 375 nanometers and 425 nanometers.

12. The apparatus according to claim 1 , wherein said UVLED source emits electromagnetic radiation of wavelengths mostly between about 395 nanometers and 415 nanometers.

13. The apparatus according to claim 1 , wherein at least 80 percent of the electromagnetic radiation emitted by said UVLED source has wavelengths within a 30-nanometer range.

14. The apparatus according to claim 1 , wherein the emission angle α is between about 30 degrees and 120 degrees.

15. The apparatus according to claim 1 , wherein the emission angle α is between 30 degrees and 60 degrees.

16. The apparatus according to claim 1 , wherein the emission angle α is between about 40 degrees and 50 degrees.

17. A system for curing a coated glass fiber, comprising:
a first apparatus and a second apparatus each according to claim 1 ;
wherein the first line focus of the first apparatus is distinct from the first line focus of the second apparatus; and
wherein the second line focus of the first apparatus is the same as the second line focus of the second apparatus.

18. An apparatus for curing a coated glass fiber, comprising:
a substantially closed, substantially cylindrical cavity having a substantially elliptical cross-section and a reflective inner surface, said cavity defining a first line focus, a second line focus, and a major axis intersecting the first line focus and the second line focus, the second line focus defining a curing axis;
a protective tube that is substantially transparent to ultraviolet (UV) radiation, said protective tube surrounding the curing axis;
an ultraviolet light emitting diode (UVLED) source positioned within said cavity; and
a lens for focusing UV radiation from said UVLED source toward the first line focus, said lens positioned within said cavity;
wherein, at the first line focus, said UVLED source and said lens are together configured (i) to provide an emission pattern that defines a line of average emission Lavg and (ii) to have an emission angle α between the major axis and Lavg defined by the following equations:
α≧θ source /2+arctan( r tube /(2 f )), and

α≦2π−(θ source /2+arctan( r tube /(2 f ))),

where
r tube is the radius of the protective tube,
2f is the distance between the first line focus and the second line focus, and
θ source is the angle of the emittance cone that contains 95 percent of the power directed from the first line focus.

19. The apparatus according to claim 18 , wherein the emission angle α is between 30 degrees and 120 degrees.

20. An apparatus for curing a coated glass fiber, comprising:
a substantially closed, substantially cylindrical cavity having a substantially elliptical cross-section and a reflective inner surface, said cavity defining a first line focus, a second line focus, and a major axis intersecting the first line focus and the second line focus, the second line focus defining a curing axis;
a protective tube that is substantially transparent to ultraviolet (UV) radiation, said protective tube surrounding the curing axis;
an ultraviolet light emitting diode (UVLED); and
an optical fiber having a first end and a second end;
wherein the first end of said optical fiber is coupled to said UVLED source;
wherein the second end of said optical fiber is positioned within said cavity at the first line focus, the second end of said optical fiber configured (i) to provide an emission pattern that defines a line of average emission Lavg and (ii) to have an emission angle a between the major axis and Lavg defined by the following equations:
α≧θ source /2+arctan( r tube /(2 f )), and

α≦2π−(θ source /2+arctan( r tube /(2 f ))),

where
r tube is the radius of the protective tube,
2f is the distance between the first line focus and the second line focus, and
θ source is the angle of the emittance cone that contains 95 percent of the power directed by said optical fiber from the first line focus.

21. The apparatus according to claim 20 , wherein the emission angle α is between 30 degrees and 150 degrees.

Assignees

• Draka Comteq Bv
• Draka Comteq Bv

Inventors

• Molin Denis

Classifications

• B05D7/20

  to wires (for insulating electric cables H01B13/16) · CPC title

• C03C25/12

  General methods of coating; Devices therefor · CPC title

• C03C25/6226

  Ultraviolet · CPC title

• B05D3/067 Primary

  Curing or cross-linking the coating · CPC title

• C03C25/00 Primary

  Surface treatment of fibres or filaments made from glass, minerals or slags · CPC title