PROBLEM TO BE SOLVED: To estimate a skin internal pigment density at a scientifically appropriate level using Kubelka-Munk theory, and to also recognize the state of a horny layer further.SOLUTION: An equation (1) is used as an estimation equation for spectral reflectance of the skin, and an estimate value Rest(λ) of the spectral reflectance of the skin is calculated with at least one of the spectral transmittance of the horny layer, the interface reflectance of a horny layer surface, the skin internal pigment density, the thickness of epidermis and the thickness of dermis as a parameter. The estimate value Rest(λ) for making a difference, between the estimate value Rest(λ) and an actual measurement value Rmeasure(λ) of the spectral reflectance of the skin, smaller than a specified value or for minimizing the difference is obtained, and the skin is evaluated by the parameter used for the calculation of the estimate value Rest(λ).COPYRIGHT: (C)2013,JPO&INPIT【課題】クベルカムンク理論を用いて、科学的に妥当なレベルで皮膚内部色素濃度を推定し、さらに角層の状態も把握可能とする。【解決手段】皮膚の分光反射率の推定式として次式(1)を使用し、角層の分光透過率、角層表面の境界面反射率、皮膚内部色素濃度、表皮の厚み及び真皮の厚みのいずれか一つ以上をパラメータとして皮膚の分光反射率の推定値Rest(λ)を算出し、該推定値Rest(λ)と皮膚の分光反射率の実測値Rmeasure(λ)との差が規定値よりも小さくなる、または差が最小になる推定値Rest(λ)を求め、その推定値Rest(λ)の算出に用いたパラメータで皮膚を評価する。【選択図】図1
