Abstract: A printer includes a device main body having a recording head, and a double-sided printing unit that forms an inverting transport path for inverting a medium fed from the side on which the recording head is located and that is configured to be mountable in and removable from the device main body. A photosensor that detects paper within the double-sided printing unit when the double-sided printing unit is mounted in the device main body detects the paper within the double-sided printing unit via an opening provided in an upper area of the double-sided printing unit.

Abstract: A printer includes a lower tray and an upper tray disposed above the lower tray. An optical sensor which detects the presence or absence of a sheet is disposed above the upper tray. The upper tray is disposed to be slidable. A sliding operation of the upper tray enables modes to be switched over between a mode where the optical sensor opposes the upper tray and a mode where the optical sensor opposes the lower tray. One sensor can detect the presence or absence of the sheet in multiple trays.

Abstract: A recording medium feeding device includes a lower stage side tray which stores a recording medium, an upper stage side tray which is provided above the lower stage side tray and stores the recording medium, a first separation inclined surface which is opposite to a tip of the recording medium which is stored in the lower stage side tray and the upper stage side tray and extends along a feed path of the recording medium, and a second separation inclined surface in which a trailing end in the feed path is positioned below a bottom surface of the upper stage side tray, and thus, which is opposite to the tip of the recording medium which is stored in the lower stage side tray and is not opposite to the tip of the recording medium which is stored in the upper stage side tray.