Efficient LED spatial measurement to improve optical modeling

Illumination engineering is a field that spans many topics and the number industries that actively work in the field is expanding. In this field the efficiency of the design is only a part of the design. Of nearly the same importance is the distribution of the light at the target. Many times the factors that are necessary to develop an illumination system will contradict one another, thus making the design of illumination systems complex and demanding. Optical modeling plays a basic role in obtaining new models. In general, the LED optical model obtains its parameters as a mathematical transformation or the average of a large set of measured experimental data. The main goal of this paper is to measure directly the parameters of the LED optical model. We use the typical LED spatial distribution model based on ray distribution. The basic parameters of this model are: the slope of the ray and the energy of each ray. The measurement system incorporates the slope measuring method used in deflectometry into an energy measurement technique. The method was tested using the measured data of two LEDs to analyze the illumination distribution provided at the image screen of standard Köhler illumination system.