Abstract: A low-cost and small-size image reader incorporating a variable power function. An original document is irradiated with the light from a light source. The light is reflected in a reading position. The reflected light is incident on a mirror block via a fixed mirror. The light incident on the mirror block is deflected by a pair of mirrors. An optical path is thus extended and shortened in its length without taking a space in the horizontal directions of the reader. The mirror block and the lens are provided with driving devices. The mirror block and the lens are moved to adjust a focal point and a magnification.