A flat cable (301) is disposed along a direction of reciprocating movement of a carriage (122), and is configured to input a synchronization signal to a board mounted on the carriage (122). A conductive plate (311) is supported by a casing (331) such that, when portions of the flat cable (301) face each other as a result of the flat cable (301) being bent according to the reciprocating movement of the carriage (122), the conductive plate (311) is interposed between the facing portions of the flat cable (301). An elastic member (312) is configured to electrically connect the conductive plate (311) and a ground member (321), and has a substantial inductance component that absorbs vibration generated in an image forming portion (140) or an image reading portion (120).