June 8th, 2016 | OPTIS group
Standard Optical Design tools use mostly very theoretical shapes and surface characteristics. For examples very often Asphere Equations are used, which is a very good method to describe mathematically Optical Elements like lenses which are produced by a grinding machine. In these machines the lens is produced from a glass block to a lens by several polishing processes. The deviations from the sphere are described by the aspheric equations which are of such shape that it is easy to calculate the optical deviation using simple equations.
Today’s manufacturing processes are much more complex, it is possible to produce with today tooling machines any free form shape in plastic lenses. OPTIS has been integrating Optical Design tools in CAD platforms as SolidWorks. But the optical designer needs to take into account that the CAD geometry is an idealistic description of the surface. Using CNC machines to create the mold, the material and material preparation, parameters like stand time in the tools and pressure used in injection molding as well as the temperature of the melted plastic have enormous influence on the final result.
Similar for the surface definition, many optical designers are using surface states like “optically polished” or “perfect mirror” when designing the optics. But these are again surface only existing in theory, the final surface state of the product will be much different. In the end, the optical designer is defining very small deviations and tolerances because he is afraid that his concept will not work, which leads to complicated production processes and a high cost for the final product.