Contact area measurement device and method for measuring contact area

Abstract

A novel contact area measuring apparatus is provided. The contact area measuring apparatus includes a light transmissive substratein contact with a specimen, illumination means for illuminating the light transmissive substratewith white light from the opposite side of the light transmissive substrateto the specimen, interference image acquisition meansfor acquiring an interference image produced by the light reflected off the specimenand the light reflected off the light transmissive substrate, intensity histogram creation means for creating an intensity histogram from information on the intensity of the interference image, and contact area computation means for calculating a contact area from the intensity histogram. The interference image acquisition meansacquires an interference image and information on the intensity of the interference image. The intensity histogram creation means forms separate RGB intensity information from the information on the intensity of the interference image and creates a G-intensity histogram. The contact area computation means separates the intensity histogram into a plurality of normal distributions by using optimized approximation of complex normal distribution and calculates the contact area from the lowest-intensity normal distribution.