Designing a side-emitting lens using the composing method

The paper considers a design method for a side-emitting lens working with a single LED source and providing a narrow light beam in the horizontal direction within 360°. The authors deal with the composing method in the design, which is usually used to synthesize the initial scheme of the imaging systems. However, in this case, a similar approach is applied to the synthesis of a system, the task of which is to provide a certain shape and characteristics of the light beam. The stage of choosing an initial principal design and synthesis for non-imaging optics is especially important since this area is characterized by the use of so-called local optimization, the result of which strongly depends on the original system. Therefore, the stage of forming an initial approximation of the system becomes crucial. In this case, the composing method can provide the most effective choice of an initial scheme of a side-emitting lens. The application of the composing method and the theory of aberrations in the field of synthesis of the initial design of a side-emitting lens is shown. The paper describes a method for selecting the key parameters of the system, and presents the relationships that allow a preliminary evaluation of the characteristics of the designed system without the use of time-consuming calculation or optimization procedures. The presented approach makes it possible to ensure the choice of the initial point of the system for further optimization, as well as to achieve high efficiency of using the light flux by the optical system of the lens (up to 90 %), only due to the optimal size of the zones into which the beam is divided and to the optimal parameters of the generating curves. In this case, the lens profile is formed by two zones in each the profile is a conic curve, hence, the curve can be described by a small number of parameters, which is very convenient at the stage of searching the initial scheme. The proposed approach can be applied in the design of such systems, as well as applied at the stage of preliminary assessment of achievable characteristics, which can significantly speed up the development process.