Improving UV LED Light Distribution to Prevent Cure Striping

Transcription

1 Improving UV LED Light Distribution to Prevent Cure RadTech UV LED 2015 October 28, 2015 Brian Jasenak

2 AGENDA About Kopp Glass UV-LED Adoption Challenges Case Study: UV Optic Technology Comparing Optic Solutions Market Implications Conclusion 2

3 ABOUT KOPP GLASS 3

4 Nearly 90 years of expertise in lighting and optics. 4

5 About Kopp Glass Founded 1926 Closely Held Located in Pittsburgh, PA USA 127,000 Mfg. Square Feet Single Integrated Facility 110 Employees ISO:9001 Certified 98% On-time In-spec Delivery 5

6 200+ Glass Compositions UV to visible to IR wavelengths 6

7 Diverse Product Lines Industrial Equipment Medical Diagnostic Devices Calibration Equipment UV Curing Aircraft & Runway Lighting Architectural & Commercial Lighting Entertainment Lighting Obstruction Lighting 7

8 LED Disruption Across Major Markets What are the standardized testing methods? Are new designs required? Are new glass compositions needed? Can we meet chromaticity requirements with different spectral power distributions? Do we understand LEDs? Binning? Useful life? 8

9 LED Disruption in Airfield Lighting DOE funding and incentives for LEDs Market was not ready for adoption; poor understanding of LED impact 9

10 LED Disruption in Airfield Lighting Solutions to aid LED Adoption: Customized glass compositions Redesigned lenses Upgraded testing methods 10

11 UV CURING MARKET ISSUES 11

12 Push for UV LED Adoption Environmentally Friendly RoHS compliant Improved Energy Efficiency Government Regulations and Incentives UV LED Prices Dropping Better Reliability and Durability = Lower Maintenance Costs More Control and Design Flexibility 12

13 UV LED Adoption Challenges Uniform Light Distribution Quality LED Curing of Freeform Shapes and 3D Profiles Photoinitiators Tailored to Hg Spectrum Net Present Value Justification 13

14 Evolution in Light Sources Light Distribution Wavelengths Heat Management Conventional Light Sources Uniform Numerous UV and VIS wavelengths Radiated heat UV LEDs Directional Localized monochromatic wavelength Back side heat extraction Mercury Arc Lamp UV LED

15 MOLDED UV OPTIC SOLUTION 15

16 Molded UV Optic Case Study Molded optic that will: Improve uniformity of irradiance Enable a flexible or tailored working distance Increase irradiance on cure surface while maintaining the UV LED array design. 16

17 Material and Design Solutions *FILTER GLASS APPLIED IN IMAGES Two LED arrays were designed to simulate two different UV curing systems Array #1: Produced drastic striping issues Array #2: Produced a uniform light distribution 17

18 Ray Trace Simulation The arrays were simulated using TracePro 100% 100% 50% 50% 0% 0% Array Uniform Array 18

19 Optic Development Optic Design Fresnel design to maintain a thin dimension for flat window replacement Prismatic pattern on incident surface to diffuse LED striping Patent Pending High UV transmitting proprietary glass composition material 19

20 High UV Transmitting Glass Composition Glass Fused Silica Fused Quartz Silicone Plastic Case Study Glass T% 365 nm CTE (*10-7) Max Service Temp Optic Manufacturing Method Chemical Resistance 400C 1000C 950C 150C 100C 400C Fab Fab Fab Mold Mold Mold UV Resistance

21 Measurements Parameters Working Distance: 1.5 inches Measurements taken in.5 inch increments over a 5x8 inch surface area 395 nm peak wavelength T10 Minolta for measurements 21

22 Array Measurements 35% decrease in irradiance between peaks (valley) 30% increase in irradiance in the valley WITHOUT OPTIC 65% WITH OPTIC 95% 22

23 Uniform Array Measurements Same optic applied to uniform array WITHOUT OPTIC 20% increase in irradiance Additional gains possible with optimized optic WITH OPTIC Developing new optic to increase results 23

24 Results Without increasing the number of LEDs, results showed: 20% increase in irradiance 30% reduction in striping 24

25 Optic Impact = Increased Irradiance and Energy Density Lower powered LEDs can be utilized, which provide design advantages: Thermal management Reduced forward current Increased LED lifetime 25

26 Optic Impact = Increased Irradiance and Energy Density Flexible working distances Faster curing Faster line speed Improved cure quality 26

27 FREEFORM OPTICS 27

28 Beyond 2D Surfaces with Moldable Glass Freeform optics design In applications where UV light is needed on 3D surfaces, freeform covers and optics could also be beneficial 28

29 Design Flexibility with Optics for unique applications: Array protection Light directing Flexible design options Freeform Optics 29

30 SUMMARY 30

31 Summary: Results The case study lens produced: 30% reduction in striping 20% increase in irradiance 31

32 Summary: Benefits Molded glass optics provide additional benefits over flat window covers: Increased working distance Longer LED lifetime Faster line speeds and shorter processing times 32

33 Summary: Benefits Eliminates need for large reflectors and individual LED optics. Provides total array protection. Thin secondary optic enables creation of smaller UV curing systems. 33

34 Thank You RadTech UV LED 2015 For additional information, please contact: Brian Jasenak