1. EDGE LIGHTING TECHNOLOGY Efficiency, Control & Uniformity Paul Crisp (Managing Director – Fern-Howard Ltd)

2. Agenda Why Use Edge Lighting Technology? Principles of Edge Lighting Technology Different Approaches to Edge Lighting Optical Control & Application Efficiency Optical Efficiency Uniformity Fern-Howard & Rambus Reference Lightguides In Conclusion 2

3. Why Use Edge Lighting Technology? 3 LED Edge Lighting has rapidly emerged as the solution of choice for backlighting in the displays and TV market Do the benefits transfer to the Lighting Market?

4. Why Use Edge Lighting Technology? 4 Luminaire designers have always had to manage issues of: Efficiency Light Distribution Uniformity Appearance

5. Why Use Edge Lighting Technology? 5 LED is no different … Directional Output High Glare Visual Appearance Efficiency

6. Why Use Edge Lighting Technology? 6 To resolve issues of Glare and Uniformity diffusing materials are often used, but ….. The compromise is Efficiency Often with as much as 40% reduction in output

7. Why Use Edge Lighting Technology? 7 Edge Lighting offers an opportunity to produce new and exciting luminaires: But …….. Not all Edge-lit technology is the same Great uniformity Thin No hotspots Optical Control Retains LED Efficiency

8. Principles Of Edge Lighting Technology 8 Edge Lighting uses the principle of Total Internal Reflection (TIR)

9. Principles Of Edge Lighting Technology Light travels and bounces along the lightguide until it hits a disruption feature 9

10. LED Backlit Module Compared to Edge Lit Module LED’s 10 Lightguide Optical & Diffusing Films (optional)

11. Different Approaches to Edge Lighting Technology There are a range of different ways to create the optical disruption features 11 Printed Dot Chemical Etch Laser Etch Vee Grooves Embedded Optics

12. Patterning Technology Printed Dot Chemical EtchLaser EtchV-groovesEmbedded Optics Method Optics Diffuse Diffuse (1D only) Specular (ray angle control) Optical Efficiency Good Better Good Best Uniformity Good Better Good Best Manufacture- ability Fast Slow Fast 12 Comparison of Edge Lighting Approaches

13. Optical features can be varied by depth, shape, density and location and enable output distributions to be optimised to support any application area 13 At Fern-Howard we work with Rambus Inc and use their Embedded MicroLens ® Optics Optical Control Most Edge lighting systems have limited optical control and produce a diffuse output

14. 14 Optimized LED-to-light guide interface Highest Application Efficiency High Optical Efficiency + Precise Ray Angle Control = Maximum light extracted from light guide Custom controlled light output Optical Control And High Application Efficiency

15. Optical Efficiency – Why is it Important? 15 Optical Efficiency90%85%80%75%70% LED Efficacy120 L/W Drive Current83 mA System Efficacy108 L/W 102 L/W 96 L/W 90 L/W 84 L/W Data based on Samsung LM231A excluding thermal losses It is clear that higher optical efficiency can be used to create higher system efficacy

16. Optical Efficiency – Why is it Important? 16 Optical Efficiency90%85%80%75%70% Min LED Efficacy100 L/W 106 L/W 113 L/W 120 L/W 129 L/W Drive Current150 mA 140 mA 112 mA 83 mA 57 mA LED output50 L 47 L 39 L 30 L 21 L Qty of LED’s Required606477100143 % increase in LED’s / cost-+ 7%+ 28%+ 67%+ 138% Table shows LED’s required to achieve 3000 lumens @ 90 L/W Data based on Samsung LM231A excluding thermal losses However, high optical efficiency can also be used to reduce LED count and luminaire cost

17. 17 Patterning Technology Performance Comparison: Printed Dot vs. Laser Etched vs. MicroLens Test Setup Fixture Configuration 18” Hanging Pendant, LEDs on 1 edge LEDsNichia NS2X123, qty 28 Light Guide Thickness 4mm Pattern Size92.6mm x 406.4mm Back ReflectorNone DiffuserNone Edge ReflectorNone CCT3500K CRI85 Optical Efficiency

18. 18 Light-guide with embedded MicroLens optics measured 10% higher efficiency than other light- guides Extraction Technology Light Guide Thickness Total Flux % Output* MicroLens4mm609.3100% Laser4mm551.190.4% Printed4mm541.188.8% * Flux from fixture with MicroLens light guide used as the baseline Optical Efficiency

19. Optical Uniformity High Uniformity is achieved by statistical mapping of lens density across the surface of the lightguide 19

20. 20 Fern-Howard and Rambus Fern-Howard have been working with Rambus to develop edge-lit lighting products based on their extensive portfolio of Edge lighting patents and technology All our products use the Rambus Embedded MicroLens ® Optics and Lens Replication technology, and are injection moulded in our facility in the UK

21. 21 Fern-Howard, Rambus Reference Lightguides A recent collaboration with Rambus has seen us launch a range of Reference Lightguide designs

22. 22 Fern-Howard, Rambus Reference Lightguides Based on Rambus patented embedded optics technology No upfront development or tooling costs Common forms with optimised distributions Compatible with wide range of LED manufacturers Design flexibility to create the LED / optical configuration you require

23. 23 Edge lighting Technology offers Luminaire Designers the opportunity to achieve uniformity and application efficiency whilst retaining much of the inherant efficiency that LED offers Not all Edge Lighting is the same with embedded optics offering the most effective performance from the range of optical disruption techniques commonly used Our Reference Design range of Edgelit lightguides enables access to Rambus patented embedded optics technology without upfront development and tooling costs

24. 24 Thank you for the opportunity to present to you today Are there any questions?