Generating-function approach for double freeform lens design

Freeform lens design for LED collimating illumination.

We present a simple freeform lens design method for an application to LED collimating illumination. The method is derived from a basic geometric-optics analysis and construction approach. By using this method, a highly collimating lens with LED chip size of 1.0 mm × 1.0 mm and optical simulation efficiency of 86.5% under a view angle of ± 5 deg is constructed. To verify the practical performanc...

Freeform LED lens for uniform illumination.

Light flux from LED must be redistributed to meet the needs of lighting in most cases, a new method is proposed for its secondary optic design. Based on refractive equation and energy conservation, a set of first-order partial differential equations which represent the characters of LED source and desired illumination were presented. The freeform lens was constructed by solving these equations ...

A Mthod for Generating the Turbulent Intermittency Function

A detection method based on sensitization of a squared double differentiated signal is developed which discriminates the turbulent zones from laminar zones quite accurately. The procedure adopts a variable threshold and a variable hold time of the order of the Kolmogorov time scale. The output file so generated, includes all the information for further analysis of the turbulent signal.

Supporting Reuse in Freeform Shape Design: a Signal Processing Approach

Reuse of freeform shape is of great importance in industrial design. This paper presents a novel technique for supporting reuse in freeform shape design based on signal processing approach. By treating the freeform feature as 2D surface signals, local shape manipulations are implemented by handling the corresponding Fourier spectrums. Techniques for feature retrieval are explored, and algorithm...

Ontology Approach in Lens Design