;FIG. 6 is a timing chart of the third embodiment;FIGS. 7A to 7C, when combined as shown in FIG. 7, show a constructional diagram of a conventional color CCD linear image sensor;FIG. 8 is a diagram of spectral transmission characteristics of color filters of the conventional color CCD linear image sensor;FIG. 9 is a diagram of spectral energy distribution characteristics of a light source which is