PURPOSE: To obtain a read picture at a photodetector face with high accuracy by controlling a driving means so as to adjust a color resolving means in an image forming optical path and a color aberration correcting means simultaneously.

CONSTITUTION: Both of a color resolving means 11 resolving a reflecting light lto red, green and blue colors provided in an image forming optical path and a color aberration correcting means 12 correcting color aberration caused by difference of wavelengths of each color and a deviation of an optical path length caused by the color resolving means 11 are simultaneously adjusted by driving means 13, 14 based on the control of a control means 15. The color resolving means 11 is a color glass filter, whose thickness is adjusted in response to the wavelength of each color resolved and the internal transmission rate, the color aberration correcting means 12 is parallel glass transmission plates whose thickness and refractive index are set corresponding to each resolved color. Through the constitution above, the out of focus and the color aberration caused in the lens image forming system are suppressed and high color accuracy is warranted and the color reading with high accuracy is attained.