Estimation of Surface Topography using Collimator and Telecentric Optical Systems

摘要

Both of gloss and gloss unevenness are important quality forrnprinting paper. It is difficult to measure gloss unevenness ofrnprinting paper with gloss meter. It is assumed that glossrnunevenness is caused by surface topography. Thus, measuringrnsurface topography is useful in evaluating gloss unevenness. In thisrnpaper, we propose a new method that is composed of a collimatorrnoptical system and a telecentric optical system for the low pricernand quick evaluation. The statistical properties of the surfacernnormal distribution are acquired by the collimator optical system.rnThe spatial frequency property of the unevenness is acquired by therntelecentric optical system. To estimate surface topography, wernassume that surface topography is expressed as the Perlin noise.rnThe method is proposed to derive the parameters which decidernabout the Perlin noise model from the measured statisticalrnproperties. We estimate the surface topography with this methodrnand verify the validity of the proposed model.