Simultaneously Multiple Surface Design Method For Led Collimator Based On Nonimaging Optics

As a new revolution of environmental friendly source, the Light Emitting Diode has the advantages such as smaller size, longer service life, higher electro-optical efficiency, energy conservation and environment protection. But due to the special distribution of light intensity, traditional luminaries can not fulfill the optical design requirement of LED light source or bring LED’s superiorities into fully play, either. In order to improve the service of LED light source, a design according to the characteristics of LED is necessary. Because of smaller beam divergence angle of collimators, the nonimaging optical design for LED collimator is of great difficulty, and is a key research point in the nonimaging optics.The theory of nonimaging is the basis of the optical design requirement of LED light source. In order to simplify the design methods, the principle of marginal ray is often used, that is, the marginal ray of the light source is still the marginal ray on the receptive aspect after reflection/refraction through optical components. Refraction type, Reflection type and Mixture of refraction and reflection are mainly adopted, of which the target of optical design is to construct light surface to change the distribution of rays. Designing several surfaces at the same time with SMS methods is possible. Two wave fronts with a certain intersection angle are firstly chosen, and then the outline of the two optical surfaces is figured out. With these figures, the marginal ray given out by the edger of LED should be perpendicular to the corresponding wavefront after reflection. Construct the acquired light surface into an entity, and it is a SMS optical component.The results of this thesis are listed as follows:1. According to the adoption of the SMS in the LED collimated light distribution, the combination of compound parabolic surface and SMS optical component is put forward. The optical element acquired can decrease the angle of divergence given out by the LED light source to about5°, as well as a distribution pattern with good uniformity.2. A systematical nonimaging optical design method for LED collimators is proposed. With this method, a new collimated light which has good collimation and high efficiency, is designed. And the methods of modeling, simulation and result-analysis are discussed in detail.3. Two-dimensional reflection, three-dimensional reflection, reflection, two-dimensional refraction, and refraction are mainly studied in this thesis. These devices use CPC to distribute light and control the angle of divergence within45°. The results of the simulation conclude that two-dimensional reflection can acquire a circular spot in the distance with the divergence angle less than2.26°, beam uniformity more than0.91and the efficiency of light79percent. Three-dimensional reflection acquires a relatively regular square contour in the distance with the divergence angle about3.66°and the efficiency of light more than63percent. Two-dimensional refraction can acquire a circular or square illumination distribution according to different shapes of the light source, and the efficiency can be more than80percent.4. Based on the SMS method of nonimaging optics, some ways for LED light source collimating optical components design are put forward in this thesis. The results of modeling show that SMS collimating optical components can decrease the angle of divergence, and achieve a good illumination distribution in the certain distance. At the same time, it is shown that design of SMS is only suitable for appliances with small angle of divergence, such as LED collimation and projection light source. That is to say, further research on appliances with large angle of divergence such as interior illumination and road lighting is needed, which indicates that the designs of SMS has a lot of research tasks.