Reflector Design Study For LED Integrated Light Source

LED is replacing the traditional light source gradually and become the new darling in the lighting area with the concept of " green lighting " enjoying popular support, because LED has many advantages, such as low power consumption、long life、no pollution and so on. However, LED is very different from the traditional light sources in structures and optical properties. It can not be applied in lighting directly and must go through special optical systems.The main optical design programmes include len and reflector. But for lens with two translucent surface, if slight deviations are found in any surface of them or impurities are found in lens, it will be a great effect on the light distribution. Furthermore the high absorption rate of lens is not conducive to save energy. And reflectors in theory with only one reflective surface have the advantages of easy processing and less loss of energy. This paper based on non-imaging optical、feedback optimization and free-form theory have researched reflector design for the LED integrated light source under different lighting conditions such as indoors、tunnels and roads. The main contents are as follows.1.Downlight reflector design for the LED integrated light source:Based on optical design of LED point source, reflector of integrated light source with good lighting effects is designed by using feedback optimization according to the law of flux conservation and Snell’s law. Using the method, we design the reflectors of downlight with light angles20°45°and60°. The illumination uniformity of the target surface are about90%, meeting the design requirements.2.An tunnel reflector design for the LED integrated light source:According to non-imaging optical principle, we establish the corresponding relationship between the point source and road, Then the reflector with the uniform rectangular intensity distribution on the target plane for integrated LED light source is obtained by using appropriate feedback optimization according to Snell’s law. Simulation results show that the light energy is limited in the rectangular area with20m x12m with overall illumination uniformity over80%. So the performance of the reflector is in line with expectations.3.An road reflector design for the LED integrated light source:The asymmetrical rectangular light distribution is needed in the multi-lane road lighting. According to non-imaging optical principle, we establish the corresponding relationship between the point source and road. Then the reflector with the uniform asymmetrical rectangular intensity distribution on the road for extended source is obtained by using appropriate feedback optimization. Simulation results show that the light energy is limited in the rectangular area with20m×12m. The horizontal illumination uniformity and vertical illumination uniformity can reach85%and80%respectively. It meets the requirements in road lighting application.