Patent ID: 7750932

Claim:
An exposing device comprising: a casing; a mirror housed in the casing; a base member fixed to the casing; a mirror supporting plate that is attached to the base member and has a mirror supporting section configured to support an end of the mirror, the mirror supporting plate having a first hole and an arcuate second hole with the first hole arranged at a center of an arc defined by the arcuate second hole; a holder member that is attached to the mirror supporting section of the mirror supporting plate, the holder member having a boss which is inserted into the first hole, the holder member being rotatable with the boss as a center around an axis of the mirror, the holder member further having a screw hole formed at a position corresponding to the arcuate second hole; a spring member that is attached to the holder member and holds the end of the mirror; and a fixing member inserted into the screw hole and configured to fix the holder member to the mirror supporting plate.