Patent ID: 8523309

Claim:
A liquid discharger comprising: a feeding mechanism configured to feed a sheet in a predetermined feeding direction; a first liquid tank configured to store first liquid for forming an image on the sheet; a first liquid discharge head comprising a first discharge hole formed to discharge the first liquid stored in the first liquid tank; a second liquid tank configured to store second liquid that acts on the first liquid so as to agglutinate or precipitate a component contained in the first liquid; a second liquid discharge head comprising a second discharge hole formed to discharge the second liquid stored in the second liquid tank, the second liquid discharge head being disposed upstream relative to the first liquid discharge head in the predetermined feeding direction; a remaining second-liquid amount detector configured to detect a remaining amount of the second liquid stored in the second liquid tank; a gap adjustor configured to adjust a gap between the first discharge hole of the first liquid discharge head and the sheet facing the first discharge hole, by moving the first liquid discharge head between a first position and a second position where the gap is smaller than when the first liquid discharge head is in the first position; a storage unit configured to store one of a plurality of quality levels regarding image quality of the image to be formed on the sheet; and a controller configured to control the first liquid discharge head, the second liquid discharge head, the feeding mechanism, and the gap adjustor so as to form the image on the sheet based on image data, wherein the controller is configured to carry out a plurality of execution modes comprising a first mode and a second mode, in the first mode, the controller controls the gap adjustor to place the first liquid discharge head in the first position, controls the first liquid discharge head to discharge the first liquid from the first discharge hole, and controls the second liquid discharge head to discharge the second liquid from the second discharge hole, in the second mode, the controller controls the gap adjustor to place the first liquid discharge head in the second position, controls the first liquid discharge head to discharge the first liquid from the first discharge hole, and forbids the second liquid discharge head to discharge the second liquid from the second discharge hole, when determining that the second liquid stored in the second liquid tank is left enough to form the image based on the remaining amount of the second liquid detected by the remaining second-liquid amount detector, the controller carries out the first mode, and when determining that the second liquid stored in the second liquid tank is not left enough to form the image based on the remaining amount of the second liquid detected by the remaining second-liquid amount detector and that the quality level stored in the storage unit is equal to or more than a predetermined level, the controller carries out the second mode.