PURPOSE: To provide the discrimination method and the apparatus, of a color, in which a light-transmitting material having an intermediate color and a shading difference can be discriminated, at high speed, as a transparent color, a brown color, a blue color, a green color and a black color which are suitable for recycling, which are comparatively low-cost and whose reliability is high.
CONSTITUTION: Transmitted light 2 Which has transmitted a transmitting material 1 is converted into an R-signal, a G-signal and a B-signal. When all values of the R-, G- and B-signals are low and all the values are not nearly 0, the color of the material is discriminated as black. When all the values of the R-, G- and B-signals are not low and all the values are nearly equal, the color is discriminated as transparency at R-output> G-output >B-output, the color is discriminated as green at G-output >B-output >R-output, and the color is discriminated as blue at B-output > G-output >R-output. When all the values of the R-, G- and B-signals are not low and all the values are not nearly equal, the color is discriminated as brown at R-output > G-output and R-output >B- output, the color is discriminated as green at G-output > R-output and G-output >B-output, and the color is discriminated as blue at B-output >R-output and B-output > G-output.
ISHII MASAMI
DEGAWA SADAO
