Search Results

Thick optical waveguides (or light pipes) which utilize optimized aspheric surfaces can greatly improve illumination efficiency in radio and instrument cluster lighting systems.[1] Stereolithography (SL) is the ideal way to generate fast, cheap light pipe system prototypes. However, to effectively analyze SLA produced aspheric light pipes, the material and physical effects of SLA fabrication have to be determined and isolated from the part geometry. Therefore, this paper presents optical characterization of SLA fabricated light pipes and a comparison of an injection molded aspheric light pipe to SLA fabricated aspheric light pipes. The feasibility of effectively using SLA prototyping for precise aspheric surfaces is discussed.

Thick optical waveguides (or “light pipes”) which utilize aspheric surfaces are shown to greatly improve illumination system efficiency over those that use linear or spherical surfaces only. An aspheric collection optic that is tailored to the filament of a particular bulb is demonstrated. Bending light around a ninety degree turn is also investigated, and the use of aspheric surfaces is once again shown to be more effective than linear or spherical mirrors. Optical design software is used to provide illustrative examples of general problems and solutions that are often encountered in waveguide illumination system design.

Computer analysis is quickly becoming the most important tool in the design of thick waveguide illumination systems used in car radios and dashboards. Used correctly, computer modeling decreases waveguide design time and increases cost effectiveness. This paper presents examples of computer analysis. First, modeled sources such as tungsten filaments and miniature booted bulbs are presented. Computer simulation of thick optical waveguides illuminated with these sources will then demonstrate the correlation between experimental measurement and computer model output. Output coupling is also modeled and the results provide information about the amount, uniformity, and directionality of the output flux. All of this information is of the utmost importance to an illumination system designer.

We will discuss a new approach for the design and evaluation of display panel waveguide illumination systems. We use the theories of radiometry and nonimaging optics to model flux transport in these systems. Our design process consists of theoretical modeling, prototyping, and direct measurement of illumination system components. Using this design process, we are able to produce illumination system components which deliver bright, uniform illumination to all areas on the panel. This design process results in an optimized design before production tooling begins. This effort reflects how private industry can increase competitiveness by using university resources.

We will discuss our cooperative effort between university research and private industry on modeling, testing, and design of optical systems for illuminating automobile dashboard systems. Under this project, we are developing models and algorithms that yield cost-effective and optimized configurations: simple designs that provide uniform illumination using the fewest number of bulbs. This effort reflects how private industry can increase its competitiveness using university resources.

We are using principles of radiometry and nonimaging optics to model and test flux collection and transportation in thick optical waveguides. Output from these systems is used to illuminate automobile dashboard clusters and radio modules. Starting with the bulb, we determine the input flux distribution. We then demonstrate how the waveguide collects and transports flux down its length. We will discuss ways of controlling and optimizing this process.