織物の光沢表示の一方法

抄録

Reflection characteristic of textile fabrics is that, when compared with that of metals, tiles, paper or the like, the diffusion of light is large and the specular reflection is extremely small, hence the degree of gloss does not vary much. For such materials, the gloss is best to be regarded as related to diffusivity and “diffused -gloss value D_n” is introduced which is defined by
D_n=1/B(θ_s)_??_B(n-i·Δθ)
where B(θ): brightness in the direction θ of reflected light,
θ_s: angle of specular reflection,
Δθ=θ_s/n
i=0, 1, 2, ……n.
D_n can be evaluated by assigning D_n=1 for mirror surface and D_n=1+n for perfect diffusive surface.
In the evaluation, the shape of goniophotometric curve is taken into account.
D_n×B(θ_s) approximates to the total amount of reflected light.
For surfaces of large diffusivity, the difference in gloss values can be given magnified, while for surfaces of small diffusivity, it can be reduced within a narrow range.
Grading of gloss by the proposed device is applied to actual goniophotometric curves, and discussion is given on the method of representing it in diagram.