Research on light distribution and heat dissipation technology based on high-power LED lamps

   Imaging optics of high-power LED lighting fixtures In the design of imaging optics, the optical system is the main imaging tool. The law of light propagation is mainly studied through the concept of geometric light. There is a lack of corresponding research on the changes caused by the transfer of energy in light propagation. However, non-imaging optics is different from imaging optics. From the perspective of physics, it is believed that light carries corresponding radiation energy during the propagation process, so the direction of light propagation is also the propagation direction of the corresponding radiation energy. Therefore, from the perspective of studying energy changes, the optical system itself is also a medium for transmitting the corresponding radiation energy, and the light propagation process itself is also the corresponding energy transmission process. The theory of non-imaging optics mainly studies the entire optical system from the perspective of the law of energy propagation. The main purpose of the application of non-imaging optical theory is to study the entire lighting system, but this lighting system itself plays a controlling role in the transmission of light energy during the propagation of light, rather than playing an imaging role similar to the imaging optical theory. However, the imaging problem cannot be excluded from the non-imaging design. The non-imaging optical theory is mainly generated to solve two major problems. One is how to maximize the energy transmitted, and the other is how to obtain the illumination distribution that meets the lighting requirements on the target plane. These two problems are usually called light collection and illumination in the field of general lighting. Concentrators can usually be divided into two categories, one is called a three-dimensional concentrator, and the other is a two-dimensional concentrator. The two-dimensional concentrator can also be called a linear concentrator. The convergence ratio of a linear concentrator is usually expressed by the ratio of the input to output dimensions on the cross section. For two-dimensional concentrators and three-dimensional concentrators (with axial symmetry), the maximum value of c can be obtained. Assuming that the input and output media have the same refractive index, when a circular light source emits light at an infinite distance with a divergence angle of iθ. When passing through the optical system, the maximum value of the convergence ratio maxC reaches 21/siniθ, and when the angle of the outgoing light and the outgoing surface converge to form a secondary light distribution. The optical expansion has a certain physical meaning: the optical expansion can be used to evaluate the impact of optical components on the energy utilization of the entire optical system, and can also be used to describe the characteristics of the light beam itself. For specific optical components, the optical expansion represents the optical component's ability to converge the light beam. Using the concept of optical expansion, the degree of matching between the lighting system and the imaging system can be determined.

3 High-power LED lighting fixture lens model

For an ideal optical system, when reflection, refraction, scattering and other losses are not considered, the optical expansion degree is conserved after the light beam passes through the optical system. In non-imaging optical design, this is a very important factor that needs to be considered in the design process. It should be said from two aspects. For the light source, the smaller the optical expansion degree, the better. However, for optical elements, the situation is just the opposite. The optical expansion degree should be as large as possible for optical elements. Of course, the larger the optical expansion degree, the better. Because the increase in optical expansion degree does not necessarily bring the same degree of energy efficiency improvement to the entire optical system, it will cause a significant increase in the complexity of optical system design and production costs. Therefore, when designing a non-imaging optical system, the concept of optical expansion degree should be reasonably used to control the trend of light and realize the conservation of optical expansion degree, so as to obtain the ideal light energy utilization rate and meet the requirements of the lighting uniformity index. The solid model of the lens can be obtained by rotating the curve around once. The outer surface of the lens model of the high-power LED lighting fixture is the desired free surface as shown in Figure 2.