To improve performance through an increased attenuation rate of a stray luminous quantity and to reduce the cost through reduction in man-hours by sequentially reducing a refractive index of a core, a clad and an absorbing body in a lens array.

A fiber 32 of a lens array 26 is made up of a core 33, a clad 34 surrounding an outer circumference of the core 33, and an absorbing body 35 further surrounding the outer circumference of the clad 34, and forming is conducted by extrusion and thermal-fusion or the like. The core 33, the clad 34 and the absorbing body 35 are made of glass of a multi-component system and the refractive indices of the core 33, the clad 34 and the absorbing body 35 are selected to be of a relation: core > clad ≥ absorbing body. The transmission rate is maintained in the core 33, by selecting the refractive index to be of the relation core > clad, and the transmission distance of the stray light passing through the absorbing body 35 is extended by setting the relation clad ≥absorbing body to increase the attenuation rate of the stray light and to reduce the stray light, made incident onto the light-receiving window of the other light-receiving element. Thus, the contrast and color information of the original is read with high accuracy.