1513 Evaluation for surface texture of micro lens mold using non-contact light scattering method
Details
The micro lenses quality strongly depends on the nano surface texture of the injection lens mold (e.g. pick-up lenses for DVD). The mold thus requires high quality surface having the roughness of less than 5nm Rq, without any flaw. However, the mold surface texture is mainly estimated, from examining the lenses formed by injection mold process, that is not quantitative but qualitative. In this study, we have developed an automated scattering light measurement system, which enables 3-D detection of the scattered light toward the various directions caused by flaws and roughness, in order to manufacture the high quality lens with high productivity. Light scattering method is used to characterize the surface texture. When the light is scattered, its polarization, as well as its scattering intensity and direction, is changed. The changes depend on the surface texture and material, as well as the polarization and an incident angle of the beam.
