LED modifying apparatus and method

• US 7,202,490 B2
• Filed: 06/16/2004
• Issued: 04/10/2007
• Est. Priority Date: 12/02/2003
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Phillips, David L., Hofeldt, David L., Lai, Jack W., Benson, Peter T., Aguirre, Francis M., Craton, Michele A.
• Primary Examiner(s): Wells; Nikita
• Application Number:
  US10/869,236
• Publication Number:
  US 20050116178A1
• Time in Patent Office: 1,028 Days
• Field of Search: 250/492.1, 250/491.1, 250/504.R, 250/504.H, 433/29
• US Class Current: 250/504.00R
• CPC Class Codes: A61C 19/003 Apparatus for curing resins by radiation
• CPC Class Codes: A61C 19/004 Hand-held apparatus, e.g. guns
• CPC Class Codes: F21K 9/69 Details of refractors forming part of the light source
• CPC Class Codes: F21V 29/80 with pins or wires
• CPC Class Codes: G02B 6/06 the relative position of the fibres being the same at both ends, e.g. for transporting images
• CPC Class Codes: G02B 6/4201 Packages, e.g. shape, construction, internal or external details
• CPC Class Codes: G02B 6/4206 Optical features G02B6/4207, G02B6/421 take precedence
• CPC Class Codes: G02B 6/423 using guiding surfaces for the alignment
• CPC Class Codes: G02B 6/4231 with intermediate elements, e.g. rods and balls, between the elements
• CPC Class Codes: G02B 6/4249 comprising arrays of active devices and fibres
• CPC Class Codes: G02B 6/4269 with heat sinks or radiation fins
• CPC Class Codes: G02B 6/4298 coupling with non-coherent light sources and/or radiation detectors, e.g. lamps, incandescent bulbs, scintillation chambers

Abstract

A radiation modifying apparatus comprises a plurality of solid state radiation sources to generate radiation that modifies a first material such as by curing or creating alignment through polarization. The solid state radiation sources can be disposed in an array pattern. Optical concentrators, arranged in a corresponding array pattern, receive radiation from corresponding solid state radiation sources. The concentrated radiation is received by a plurality of optical waveguides, also arranged in a corresponding array pattern. Each optical waveguide includes a first end to receive the radiation and a second end to output the radiation. The radiation modifying apparatus can be utilized for continuous substrate, sheet, piece part, spot curing, and/or 3D radiation-cure processes.

Claims

1. An irradiation apparatus, comprising:

a plurality of solid state ultraviolet radiation sources to generate radiation that modifies a first material;

a plurality of optical concentrators, wherein each concentrator receives ultraviolet radiation from one or more of the plurality of solid state radiation sources;

a plurality of optical waveguides, wherein each of the plurality of optical waveguides includes a first end and a second end, wherein each first end receives ultraviolet radiation from one or more of the plurality of optical concentrators;

a support structure to stabilize at least a first portion of the second ends of the plurality of optical waveguides; and

a first lens placed in the path of the ultraviolet radiation emanating from the second end of the waveguide that alters the path of the ultraviolet radiation;

a polarizer disposed in the path of the radiation emanating from the first lens; and

a second lens placed in the path of the ultraviolet radiation emanating from the polarizer.

2. The irradiation apparatus of claim 1, wherein the first lens alters the path of the radiation by focusing the radiation.

3. The irradiation apparatus of claim 2, wherein the first lens is a cylindrical lens.

4. The irradiation apparatus of claim 1, wherein the first lens alters the path of radiation by diffusing the radiation.

5. The irradiation apparatus of claim 4, wherein the first lens is a diffractive optical element.

6. The irradiation apparatus of claim 1, wherein the first lens alters the path of radiation by collimating the radiation.

7. The irradiation apparatus of claim 6, wherein the first lens is included within a lenslet array.

8. An irradiation apparatus, comprising:

a plurality of solid state ultraviolet radiation sources to generate radiation that modifies a first material;

a plurality of optical concentrators, wherein each concentrator receives ultraviolet radiation from one or more of the plurality of solid state ultraviolet radiation sources;

a plurality of optical waveguides, wherein each of the plurality of optical waveguides includes a first end and a second end, wherein each first end receives ultraviolet radiation from one or more of the plurality of optical concentrators;

a support structure to stabilize at least a first portion of the second ends of the plurality of optical waveguides;

a lenslet array with each lenslet of the lenslet array being matched to one of the plurality of optical waveguides, the lenslet array collimating the ultraviolet radiation emanating from the second ends of the optical waveguides; and

a polarizer placed in the path of the ultraviolet radiation emanating from the lenslet array such that the lenslet array provides the ultraviolet light within an acceptance cone of the polarizer.

9. The irradiation apparatus of claim 8, wherein the lenslet array is bowed to focus the ultraviolet radiation onto the polarizer.

10. The irradiation apparatus of claim 8, further comprising an optical element placed in the path of the radiation emanating from the polarizer.

11. The irradiation apparatus of claim 8, wherein the optical element placed in the path of the radiation emanating from the polarizer is a lens.

12. The irradiation apparatus of claim 8, further comprising a light valve that deflects high angle radiation emanating from the waveguide to reduce the angle of radiation reaching the polarizer.

13. An irradiation apparatus, comprising:

a plurality of solid state radiation sources to generate radiation that modifies a first material;

a plurality of optical concentrators, wherein each concentrator receives radiation from one or more of the plurality of solid state radiation sources;

a plurality of optical waveguides comprising fibers, wherein each of the plurality of optical waveguides includes fibers having a first end and a second end, wherein each first end receives radiation from one or more of the plurality of optical concentrators, and wherein a plurality of the second ends each forms a separate lens that alters the path of radiation from the corresponding second end by collimating it relative to the radiation emanating from other second ends; and

a support structure to stabilize at least a first portion of the second ends of the plurality of optical waveguides.

14. The irradiation apparatus according to claim 13, further comprising a polarizer disposed in the path of the radiation emanating from each of the lens.

15. The irradiation apparatus of claim 14, further comprising a second optical element disposed in the path of the radiation emanating from the polarizer.

16. An irradiation system, comprising:

a solid state radiation source, comprising

a plurality of LED dies to generate ultraviolet radiation that modifies a radiation modifiable chemical formulation;

a plurality of optical concentrators, wherein each concentrator receives ultraviolet radiation from one or more of the LED dies;

a plurality of optical fibers, wherein each of the plurality of optical fibers includes a first end and a second end, wherein each first end receives concentrated ultraviolet radiation from one or more of the plurality of optical concentrators;

a first lens placed in the path of radiation emanating from one or more of the second ends of the plurality of optical fibers;

a polarizer disposed in the path of the radiation emanating from the first lens; and

a light valve disposed in the path of the ultraviolet radiation emanating from the polarizer that rotates an angle of polarization of the ultraviolet radiation;

a second polarizer disposed in the path of the radiation emanating from the light valve;

a second lens placed in the path of the ultraviolet radiation emanating from the second polarizer; and

a substrate to support the radiation modifiable chemical formulation.

17. The irradiation apparatus of claim 16, wherein the ultraviolet radiation cures the radiation modifiable chemical formulation.

18. The irradiation apparatus of claim 16, wherein the radiation modifiable chemical formulation comprises liquid crystals and wherein the liquid crystals are aligned by the radiation.

19. An irradiation system, comprising:

a solid state radiation source, comprising

a plurality of LED dies to generate ultraviolet radiation that modifies a radiation modifiable chemical formulation;

a plurality of optical concentrators, wherein each concentrator receives ultraviolet radiation from one or more of the LED dies;

a plurality of optical fibers, wherein each of the plurality of optical fibers includes a first end and a second end, wherein each first end receives concentrated ultraviolet radiation from one or more of the plurality of optical concentrators;

a bowed lenticular array with each lens aligned with one of the plurality of optical fibers such that the bowed lenticular array focuses the ultraviolet radiation; and

a polarizer placed in the path of ultraviolet radiation emanating from the bowed lenticular array; and

a substrate to support the radiation modifiable chemical formulation.

20. The irradiation apparatus of claim 19, further comprising an optical element placed in the path of radiation emanating from the polarizer.

21. The irradiation apparatus of claim 20, wherein the optical element placed in the path of radiation emanating from the polarizer comprises a lens.

22. The irradiation apparatus of claim 19, further comprising a light valve placed in the path of radiation emanating from the waveguide that deflects high angle radiation to reduce the angle or radiation reaching the polarizer.

23. The irradiation apparatus of claim 19, wherein the radiation modifiable chemical formulation comprises liquid crystals and wherein the liquid crystals are aligned by the radiation.

24. An irradiation system, comprising:

a solid state radiation source, comprising

a plurality of LED dies to generate radiation that modifies a radiation modifiable chemical formulation;

a plurality of optical concentrators, wherein each concentrator receives radiation from one or more of the LED dies;

a plurality of optical fibers, wherein each of the plurality of optical fibers includes a first end and a second end, wherein each first end receives concentrated radiation from one or more of the plurality of optical concentrators, and wherein a plurality of the second ends each forms a separate optical element; and

a substrate to support the radiation modifiable chemical formulation.

25. The irradiation apparatus of claim 24, further comprising a polarizer disposed in a pathway of radiation emanating from each of the optical elements.

26. The irradiation apparatus of claim 24, wherein the radiation modifiable chemical formulation is cured by the application of the radiation.

27. The irradiation apparatus of claim 24, wherein the radiation modifiable chemical formulation comprises liquid crystals and wherein the liquid crystals are aligned by the radiation.

28. A method of modifying a material, comprising:

generating radiation from a plurality of solid state radiation sources;

concentrating the radiation received from one or more of the plurality of solid state radiation sources;

transferring the concentrated radiation through a plurality of optical waveguides by coupling each solid state radiation source into a corresponding optical waveguide dedicated to the solid state radiation source, wherein each of the plurality of optical waveguides includes a first end and a second end, wherein each first end is coupled to the corresponding solid state radiation source and receives the concentrated radiation;

stabilizing at least a first portion of the second ends of the plurality of optical waveguides;

altering the path of the radiation with a lens placed in the path of the radiation emanating from the second end of the waveguide; and

polymerizing a material with the radiation from the optical element.

29. The method of claim 28, wherein the radiation is ultraviolet radiation.