Diffusion material, diffusion material evaluating method, blending method for fine particles in the diffusion material, and production method for the diffusion material

A diffusion material comprising:

• a matrix having a refractive index;
• and
• multiple kinds of fine particles, each kind of which has another refractive index different from said refractive index of said matrix, dispersed in said matrix in accordance with blending amounts,
• said blending amounts of said multiple kinds of fine particles being determined by
• determining a light intensity attenuating rate C(λ) in said diffusion material so that chromaticity variations Δx and Δy of emitted light outgoing from said diffusion material with respect to incident light entering said diffusion material satisfy the following expression (9), respectively,
• −0.03≦Δx≦0.03
• −0.03≦Δy≦0.03 (9);
• determining a total cross-sectional area of scattering Stotal(λ) in said diffusion material at a wavelength λ of said incident light entering said diffusion material so that a condition for said light intensity attenuating rate C(λ) in said diffusion material thus determined is satisfied;
• and
• determining said blending amounts of said multiple kinds of fine particles dispersed in said matrix so that said total cross-sectional area of scattering Stotal(λ) in said diffusion material thus determined is determined as a total of cross-sectional areas of scattering S(λ) of respective fine particles that are determined by Mie theory for all of said multiple kinds of fine particles dispersed in said matrix.