Based Simulation Study And Design Of The Uniform Illumination Of The LED Array

Improvements in the continuous increase of the luminous flux of single LED have enabled the use of light-emitting diodes (LEDs) for new applications, such as indoor plant cultivation, displays and biomedical. Though modern high-power LEDs produce up to 150 lm per device, several individual LEDs must be mounted on panels to produce a practical power. Therefore, the arrangement of the LED must be designed reasonably; otherwise it will cause glare and waste light energy.The design and simulation of the LED arrays for uniform illumination systems in this paper, the major work is shown as following:1. The design is quite important for achieving a good uniform illumination distribution before a LED lighting module is produced. According to Sparrow's criterion and using Matlab and optical software TracePro, we simulate and comparative analysis the three more common LED planar array that is square, triangular and circular array by setting the three parameters: the distance between LED array and the detective screen,the number of LED array and the viewing angle of LED. As the LEDs are arranged in different ways, there have different range of uniform illumination distribution and space occupation. By comparison, the results showed that the triangular array can produce wide range flatness and occupy little space2. Based on geometrical optics and irradiation theory, a conic light-emitting diode array with uniform far-field irradiance was analyzed. Formulas for calculating total irradiance from source to collecting screen were deduced. According to Sparrow's criterion, the expression was calculated by using Matlab optimization toolbox. Furthermore, the software TracePro was used to simulate the designed array. The ray-tracing simulations show that an array of light-emitting diodes assembled upon a conic surface can produce a wider angle distribution of light field than a flat array. This paper focuses on the analysis and simulation of two-dimensional and three-dimensional of conic, and optimizes the uniformity of the illumination of a target. This method provides valuable reference to the LED lighting modules design.3. A novel LED optical model for uniform illumination system is proposed. Optical models directly effect the illuminance distribution of observed surface. Approximate Lambertian models were widely used in designing the LED arrays. But it exists some errors compared with the experimental data. In order to reduce the error caused by the approximate Lambertian model, we use curve-fitting technique to modify it. We adopt point from the curve of the LED light intensity measured experimently, then a spline curve was designed for fitting, the revised model was obtained. To verify the feasibility of the new model, we apply the model in a 4×4 array design. The result shows that, compared to the approximate Lambertian, the light intensity distribution produced by the fitting model is more uniform and intense in our fitting model.