毛髪のつや測定器の開発

Abstract

Hair luster is one of the criteria to judge the beauty of hair. Therefore, young women are interested in hair luster.Luster is one of the optical properties. The reproducibility of the data measured optically for hair luster with conventional instruments has been poor and the results obtained have been in less agreement with visual evaluation, because of the influence of color and distortions of hair samples.Maximal reflection value measured at specular reflection angle (S) and diffuse reflection value measured in the vertical direction to the plane of hair shafts (d) were obtained with goniophotometer on hair tresses with the same luster and different color. “S-d Value” was introduced as “Luster Value” to minimize the influence of color of hair. However, it was not possible to eliminate the influence of color completely by this treatment. Therefore the distribution of wavelength of diffuse and specular reflection was controlled by filters to adjust spectral response of optical detector to relative luminous efficiency curve. By these treatments, the influence of color was eliminated. The incident angle was set at 45° to make “signal noise ratio” higher and the apparatus smaller. Hair holder, which is easy to handle, was developed to keep up parallelism of hair fibers, because disorder of them had considerable influence on the measurement of hair luster.A handy apparatus, which makes hair luster measurement possible without cutting hair off, is developed. The results obtained correlate to visual evaluation.