PURPOSE: To simplify the method of put-on a wire which drives a reflecting mirror, and to improve the reliability by easily adjusting the fixation position of the reflecting mirror relative to the wire.

CONSTITUTION: One terminal of the 1st movable mirror 7 which reflects an image of an original 2 is fixed to the 1st holding base 6 and one terminal of the 2nd movable mirror 11 is fixed to one terminal of the 2nd holding base 9. A fixed mirror 14 reflects the original image which is reflected by the 2nd movable mirror 11 and transmitted through a zoom lens 13 toward a photosensitive drum 3. Long-sized holes 20c and 20d are bored in a wire fixture 20 that the wire 17 which drives both holding bases 6 and 9 engages, and the fixture 20 is shifted in fixation position to adjust the position of the 1st movable mirror 7 finely. When the wire fixture 20 is moved by L, the 2nd movable mirror 11 moves by L/2.