Abstract
The tactile roughness perception of fine-texture has been investigated by using non-uniform surface materials such as polishing papers, and it has been difficult to quantitatively discuss the relationship between physical properties of surface texture and perceived roughness. To solve this issue, we developed a novel method of making a surface plate that has close-packed structure with microparticles of single size (uniform surface), and that has pseudo-close-packed structure with microparticles of two sizes (mixed surface). In this paper, we estimated subjective equality of perceived roughness of mixed surfaces in relative to the uniform surfaces, and compared the physical properties of the mixed surface and uniform surface with perceptually equal roughness. We found that perceived roughness can be partially-explained by physical distance between relatively-bigger particles, though it is not the case when the distance is much longer than diameter of the particles.
