1. Solid State Lighting: The Future is here Xavier Fernando Ryerson University

2. Incandescent Bulb

3. LED Lamp

4. How Does LED Works?

5. Common LEDs

6. White LED

7. RGB Based White LEDs Advantages  Excellent Color Rendering (faithful color reproduction)  High lumens/watt  Color temperature can be tuned by adjusting the three colors separately  More efficient compared to phosphor based LED Disadvantages  Difficult to achieve pure white color  Lamp to Lamp color variation (u,v) is the colour coordinates

8. Blue LED with Phosphor Advantages  Temperature Stability  Simpler to create than the RGB LED  Decent colour rendering Disadvantages  Less efficiency  Weak lumens/watt  Board emission spectrum  Short lift time compare with other type of LEDs

9. Relative Energy Vs. Wavelength

10. Comparison of different light sources Incandescent Light Phosphor Based LED RGB Based LED

11. Power Conversion Efficiency Power efficiency (lumen-per-watt) is the measurement of the total amount of light emitted by a light sources per energy input.

12. Directional Illumination Lights from LEDs can be directed effectively to where it is needed, compensating for their lower luminous efficiencies.

13. Lifetime

14. LED Traffic Signals  LEDS use 80% to 90% less energy than incandescent signals  No need for colored filters  Longer life  Reduce maintenance costs Compared to filtered incandescent signals :

15. Specific Application: Signs and Contour lighting

16. Specific application: Medical Equipments

17. Future