1. Block Diagram

2. Computer Simulation

3. Color Mixing

4. Computer Design

6. Computer design

7. Outlook in Europe The Workshop on LED Manufacturing for Lighting & Displays was held in Berlin, Germany on September 10-11, 2007. Significant advances in performance will be needed to realize these expectations, as follows: Output of a single white LED to exceed 200 lumens Radiant conversion efficiency to exceed 150 lm/W Luminance greater than 50 Mcd/m2 Lifetime greater than 50,000 hours Integration into large-area panels Integration with driving electronics Resistance to harsh weather conditions

8. Advantages and challenges Luminaire manufacturers also expressed great interest in LEDs. Among the design advantages offered by LEDs the following were mentioned: Very compact dimensions of lighting fixtures Can fit in conventional light fittings; Dimming is possible without change in colour temperature; Colour of light is adjustable with use of multi-coloured LEDs, enabling dynamic colour control and high colour saturation Large range of colour temperatures Long operating life Reduced or zero maintenance costs High luminous efficiency Absence of IR and UV light Safety, because of very low voltage Very reduced amount of heat (no risk of burns) Cold switch-on (down to -40°C) and higher efficacy at cold temperatures Precise directional emission without accessories or refractors Use of efficient optics made of polymers

9. LED Eye Safety

10. Cost At present, incandescent and fluorescent lamps have a cost-per-lumen ratio of $0.03–0.05 and $0.06, respectively. To compete, the figure for LEDs needs to drop by a factor of 20. But increasing drive current to 2 A and efficacy to 150 lm/W will deliver a nine-fold improvement, which means that we can get into the right ballpark if we can halve the cost of making LEDs.

11. Outlook in USA DOE's long-term research and development goal calls for white-light LEDs producing 160 lm/W in cost-effective, market-ready systems by 2025.

12. R & D of LED

13. Thank you for your coming You and Shanghai University will have a great and bright future