PURPOSE: To improve the read performance and increase the efficiency of operation by providing the cleaning mechanism on the scanner surface of the sensor.

CONSTITUTION: When a control part rotates a stepping motor 16, a timing belt 17 moves and a block 5 and a pad fitting plate 7, a pad pressure part 8, a pad 6, a shield plate 9, etc., begin to move. When the pad fitting plate 7 leaves a stopper 13 as the block 5 moves, the pad fitting plate 7 rotates around a spring bush 20 and the tip part of the pad 6 contacts the scanner surface 4-1 of the contact sensor 4. In this state, a motor 16 rotates, so the pad 6 moves gathering dust in contact with the scanner surface 4-1. When the pad 6 reaches one end part, the back part of the pad fitting plate 7 abuts on the stopper 13 and the pad 6 leaves the scanner surface 4-1. Thus, the dust, etc., on the scanner surface 4-1 of the sensor 4 is removed by the pad 6.