Design And Research Of The Free-Form Lens Based On Reverse Feedback Optimization Method

The target of sustainable development like the ideas of energy-saving and emission-reduction and low carbon economy which are vigorously supported by our government is widely promoted. As a new Green Light, LED will cause significant changes in the lighting area. With the technology breakthrough, cost reduction and broad applications, it is now widely used in road-lighting, backlight, front light and signal lamp, etc. Apart form the chip design, LED's perpheral design must be concerned by reason of the compatibility which is caused by the differences between the LED and the traditional light sources. Therefore, in this paper we work over the LED's design to achieve illuminance uniformity by free-form method, and make improvements through the way of reverse feedback optimization.In this paper, a reverse feedback optimization method to obtain illuminance uniformity is proposed which is integrated with the forward method to get better result. First, the properties and the differences from traditional light sources are presented. Secondly, the design procedures and the softwares are introduced. Last, the method of reverse feedback optimization is proposed. And also we combine it with the forward method to improve the result. The reverse feedback optimization method is proposed based on the simulation results, which is different from the forward method on the condition of not altering the division of the targetplane. In this paper, the circular and rectangular circumstances are considered for reason of complexity. Through the combination of two methods, the illuminance uniformity increases from 60 percent to more than 90 percent in the circular circumstance; Through the reverse feedback method, the illuminance uniformity is doubled for the rectangular. The feedback method in this design is innovative and is complementary to the previous design methods, which is significant in LED's lighting system design.The free-form lens design in this paper is on the condition of illuminance uniformity under the circular and rectangular circumstances. Random targetplane lighting distribution like the illuminance nonuniformity and the luminance uniformity can be achieved because of the commonality of the theory. The research in this paper have a significant value, and in all kinds of LED lighting system design, we can refer to the idea proposed in this paper.