Study On Secondary Optical System Design For High-power LED Integrated Source

In recent years, with the concept of "green lighting" enjoys popular support, because of LED light source has many advantages, such as low power consumption, long life, no pollution, etc, so, LED is gradually replacing the traditional light source, become the new darling of the lighting area. But, the LED light source, especially the high-power LED integrated source, is very different from the traditional light sources in structures and optical properties, as a result, the existing lighting system design methods cannot be applied to the design of LED lamps. Also, the commonly used free-form surface design method is regard the single LED source as an ideal point source, but the size of LED integrated source cannot be negligible, so this methods are also can not applied to the secondary optical design for LED integrated source. Therefore, researching the secondary optical system design method for the high-power LED integrated source is particularly urgent. This subject based on non-imaging optics, edge-light theory and free-form theory, researches the secondary optical design methods for directed collimated illumination and wide range uniform illumination lighting system.Collimated illumination problem:A novel method of designing collimator system for high power LED is proposed. On the premise of having known radiation characteristics and emitting beam divergence angle of the LED source, according to the etendue conservation low to calculate the basic dimensions of the optical system, based on the edge-light theory and simultaneous multiple surface design method, iteratively calculate the surface data of the free-form, then establish the optical model.Uniform illumination of rectangular area:A new feedback optimization design method based on arithmetic sequence is proposed to design free-form optical systems for LED integrated source. In this method, the division of the mesh grids of the light source and the target surface are changed in accordance with the distribution form of arithmetic sequence to change the illuminance distribution of the target surface. So. they can cancel out the impact of a variety of error accumulation on the model and eventually achieve the desired illumination uniformity distribution. Based on the initial model, after several optimizations with the feedback method proposed in this paper, we can obtain the optical model, which meet the design requirements.With the design method proposed in this article, we designed a collimator les based on the structure of refractive-reflex-refractive, a lens which can achieve uniform illumination of rectangular area and a petal-shaped illumination distribution LED lens. Then simulating those models by using TracePro, all the results achieved the expected design requirements. Lastly,we made the petal-shaped illumination distribution LED lens and tested it, the actual lighting effects are basically consistent with the simulation results, proved the methods are correct and feasible.