Abstract: According to an embodiment, an ADF that feeds and conveys original document sheets one sheet by one sheet from a tray unit to a read position on a document glass by motive power from a driving motor includes: an opening/closing unit operable to open and close relative to the document glass; an open/close detection sensor that detects an open/closed state of the opening/closing unit; a first interlock switch, which is arranged between a power source and the driving motor, that is on when the opening/closing unit is closed, and vice versa; and a control circuit that determines the open/closed state of the opening/closing unit based on detection outputs of the first interlock switch and the open/close detection sensor. The control circuit determines that the opening/closing unit is in the closed state when the first interlock switch is on and the open/close detection sensor is detecting the closed state.

Abstract: A sheet conveying device includes: a separation sheet feeding mechanism having a paper feeding belt and a separation roller; and an adjustment mechanism that changes contact state of the paper feeding belt to the separation roller by changing relative position of the paper feeding belt and the separation roller, and changes and adjusts separation performance of the separation roller for the subsequent sheet, wherein the adjustment mechanism includes a cam follower member changing the relative position of the feeding belt and the separation roller, the cam member includes a first cam face and a second cam face which are formed at each rotation radius position in accordance with the rotation angle position, and are spaced apart in the rotation radius direction, and the cam follower member has a contact unit guided by the first cam face and the second cam face.