A printing system includes at least one main printer arranged to print images onto main sequence sheets that are passed sequentially through the main printer; an inserter arranged to insert individual sheets as insert sheets into a stream of main sequence sheets that have left the main printer, thereby to form a mixed sheet sequence; and a conveyer arranged to convey the sheets of the mixed sheet sequence one by one towards an output unit. An insert sheet printer is connected to the inserter for printing the insert sheets and forwarding them to the inserter.

In a post-processing device (sheet discharge device), a pile thickness calculating section calculates, from a type and the number of paper sheets discharged through a sheet output port, a thickness of a pile, at its leading end, of sets of paper sheets on a sheet output tray (piling section), calculates a thickness of the pile, at its trailing end, of sets of paper sheets on the sheet output tray from an amount of movement of a lifting section, and calculates an angle of inclination of the uppermost set of paper sheets in the pile from the thicknesses of the pile at its leading and trailing ends, a height of inclination of the sheet output tray, and a length of the paper sheets. The control section controls the sheet discharge section to change a manner of discharging a subsequent set of paper sheets according to the calculated angle of inclination.

When a face of a paper sheet to be discharged on which an image is formed faces downward, a paper discharge device divides an image region of image data on the paper sheet to be discharged into areas along a discharge direction, detects an area in which maximum image density for each divided area is higher than or equal to a specified threshold, and controls a discharge angle so that the detected area does not come into contact with a stacked paper sheet until the paper sheet to be discharged has been discharged from a discharge roller.

A recording device 11 includes a device main body 20 including a recording section 25; a placement tray 21 on which a medium M is configured to be placed; and a cassette 22 provided below the recording section 25 and the placement tray 21 and configured to accommodate a medium M. The device main body 20 includes a first path 41 configured to feed medium M placed on the placement tray 21 to the recording section 25 and further to transport the recorded medium and a second path 42 configured to transport medium placed on the placement tray 21 to the cassette 22.

A recording device includes a device main body 20 including a recording section; a placement tray on which a medium M is configured to be placed; and a cassette provided below the recording section and the placement tray and configured to accommodate a medium M. The device main body includes a first path configured to feed medium M placed on the placement tray to the recording section and further to transport the recorded medium and a second path configured to transport medium placed on the placement tray to the cassette.