To form an image as electronic information on the surface of sensor with high resolution while reducing it and to read that information with high accuracy by composing a device of seven lenses and satisfying specified conditions with these lenses.

This device is composed of positive 1st lens G1 and 2nd lens G2 turning its convex toward the side of original, negative 3rd lens G3 turning its concave toward the side of sensor, miniscus-shaped positive 4th lens G4 turning its convex toward the side of sensor, negative 5th lens G5 turning its concave toward the side of original, positive 6th lens G6 turning its convex toward the side of sensor, and positive 7th lens G7 turning its convex toward the side of sensor. The focal distance from G1 to G3 is defined as fF, the focal distance from G4 to G7 is defined as fR, the central thickness or air gap of i-th lens counted from the side of original while including an iris SP is defined as Di and the refraction factor and Abbe number of material for the i-th lens are respectively defined as Ni and νi. At such a time, conditions are satisfied as follows; 1.4<fF/fR<2.2, 0.8<D5/(D6+D7/N7+D8)<1.2, 1.75<N1, 1.75<N7, 16<(ν2-ν3), 16<(ν6-ν5) and 45<ν4.